14 ms·

Tinkering with electronics

192 points by ttsiodras 9y ago

platz 9y ago
I would love to see what tinkering could be done with low-power, minimal or "self-sufficient" location-placement of sensors to gather data and report data using Lora, cdma, or HF for long range. Why? Because electronics are small and there should be interesting ways to exploit the difference between this smallness and full blown CPUs operating on the grid. But I have a hard time generating good ideas. Any thoughts?
- draugadrotten 9y ago
  I'm with you. Using the Things Network https://www.thethingsnetwork.org/ https://www.thethingsnetwork.org/ I am currently setting up a gateway and connecting a few remote sensors to it. Right now I am just sending simple sensor data (button_press, temperature, light etc) but I would like to expand on this and send other data. For example I want to be able to deploy my own speed traps, measuring vehicle speeds on any road I want. I don't need to connect the speeds to reg plates, so I'm thinking about just measuring when the car passes through an IR beam or measuring a magnetic pulse or similar... Also, air quality monitoring. And of course, the robot lawn mower is getting an upgrade for the spring. Water temperature in the lake might be a good addition for summer. I forgot to say but since it is https://www.thethingsnetwork.org/ https://www.thethingsnetwork.org/ everything I do is already connected to Alexa and IFTTT... imagine waking up in the morning and having Alexa tell you that it is a good day for a morning swim, since the water is X degrees. Yum.
  - platz 9y ago
    Those are fantastic ideas - love it!
- simonbarker87 9y ago
  Making extremely low power consumption nodes is very satisfying, I made a very simple light sensor remote sensor node that could power itself from 50mg of vibration acceleration a few years back on as part of my PhD in energy harvesting. The mast challenging part was getting the pic to draw the absolute minimal current and manage the power draw of all the other systems. The current draw was so low by the end that we had to use an electrometer with a 30 giga ohm (if I remember correctly) input impedance to accurately measure the current draw. Programming in asembly was a pain but I had a lot of help on that so not awful.
  - asmithmd1 9y ago
    A high voltage meter input impedance will minimize the meter's effect on the circuit under test when measuring voltage, not current. For accurate current measurements, you want to measure the voltage drop across an accurate, low-value "shunt" resistor that carries all the current for your circuit.
    - simonbarker87 9y ago
      Correct, so we used a high impedance voltage meter across a calibrated resistor in series with the circuit under test. It was 7 years ago I did the work and now rarely work hands on with electronics so I am hazy on the exact details but it’s all in the published journal paper, which, as always with science papers is now behind a paywall. UPDATE: I miss remembered, we used the high impedance electrometer to buffer the input of a National Instruments interface board so we could record the voltage build up across the storage capacitors, if you use a normal voltmeter the caps just discarge into the voltmeter and the charge never builds up enough to allow the micro controller to turn on, run the code it needs to and then go back to sleep. You land up with some really nice sawtooth wave forms with this method and, as the acceleration on the vibrational energy harvester increases, the frequency of the sawtooth changes proportionally up to a point where the system is transmitting all the time.
- jerrysievert 9y ago
  take a look at the feather m0 from Adafruit - I have a few deployed where wifi is quite a ways away, gathering data for me and sending to another one acting as a base station. I haven't added solar, as these are inside, near power, but have some solar panels and hardware waiting for me to deploy out in the field (literally). so far, it's been my lack of good waterproof enclosures that has slowed me down. I wonder if there'd be a good opportunity for someone in that space.
  - Kliment 9y ago
    Put it in one of those sealable jars with hinges - stuff a few packets of dessicant inside to stop condensation and you're done. If you need to pass through wires score a v-shape into the seal and make sure they get squeezed tight when you close the jar. Something like http://img4.foodservicewarehouse.com/Prd/1900SQ/AmericanMetalcraft_HMJ5.jpg http://img4.foodservicewarehouse.com/Prd/1900SQ/AmericanMeta... make sure to get some extra sealing rings if you do passthroughs as it's hard to get the scoring right.
  - platz 9y ago
    But what did you use it for
  - HeyLaughingBoy 9y ago
    What opportunity do you see? There's a huge variety of different flavors of water-resistant enclosures on the market, from things that can only take light spray, to underwater-rated enclosures. Google IP-66 or NEMA4 enclosures. Also, I have at least one project that was housed in clear 3" PVC pipe since it had to go down a well. One of my favorite companies to work with in this area is Polycase.
- abraae 9y ago
  I am working on a lora/arduino mesh network for reporting back the state of a large number of traps for invasive predators (mustelids, possums, rats). The traps are spread around the countryside in dense bush/jungle. When one goes off, someone needs to tramp in and clear and reset it. Currently, there is no monitoring of any kind, so checking traps is extremely labour intensive. The trickiest aspect of this project is that each node needs to spend virtually all of its time asleep to minimise battery drain, yet for two nodes in the mesh to communicate, they both need to be awake at the same time. Drifting clocks etc. The easiest aspect is that the acceptable data rate is 1 bit every 8 hours or so!
  - icebraining 9y ago
    I'm totally ignorant about radio hardware, but I'm curious, why not use a chip with wake-on-radio?
    - abraae 9y ago
      Good idea, except that wake-on-radio requires the radio to be powered on all the time. Whereas I need to sleep everything except the arduino watchdog.
  - vkuruthers 9y ago
    What a cool and useful sounding project! Does LORA handle any of the meshing aspect, or do you have to manage that at the application level? Also what kind of node to node range are you getting from the radios, and when the users install them, how do they know they'll be within range of the next node?
    - abraae 9y ago
      Yeah, it is some fun, wish I had more free time to devote to it. LORA doesn't handle any of the mesh behaviour, I'm doing all of that using LORA just at the send and receive level. The devices I am using are moteinos - a cool arduino lora mashup https://lowpowerlab.com/guide/moteino/ https://lowpowerlab.com/guide/moteino/. I see various ranges from LORA, the environment is steep valleys and dense bush which severely dials back the range, sometimes down to a few hundred meters or even less. At this stage I haven't played around with optimising the LORA settings, but there are bound to be some wins there since the required data rate is so low. Good question about installs, my current plan is that before setting out, the user places that part of the network where they are heading into constant beacon mode. The node can then be installed, knowing there's another node within reach. In practice this should be fine anyway, as the recommended placement for traps for e.g. stoats is every 100 meters or so, so usually there will be other traps within range.
- sbr464 9y ago
  Are you referring to using something like the particle.io platform?
fairpx 9y ago
I design interfaces for a living, but tinkering with hardware is one of the most satisfying journeys I know. Every now and then, like OP, I play around with different hardware projects. It's amazing how, showing a half-baked hardware project to a friend gets them a lot more exciting than showing them a nicely designed software project. It feels like when you're tinkering with hardware a lot more parts of the brain are challenged and thus generate a more fulfilling experience. I highly recommend everyone who's into software or design but never did anything with hardware to spend some time this week building a simple blinking LED project with the Arduino. You'll know exactly what I'm talking about.
- Tade0 9y ago
  I guess half of that satisfaction can be attributed to the fact, that hardware - especially analogue - is not as lenient about errors as software. If you burn a transistor you burn a transistor - it's now useless for its original purpose, so you have to triple check everything. Also there are 2nd and 3rd order effects that require experience to catch. Example: I was really happy that my two 555 timers driving some LEDs were synchronized so good until I realized that they were plugged into the same weak power source, so the voltage drop from power surges triggered them both.
  - w-ll 9y ago
    I really got into building simple hardware while in college. For me it was about the physical aspect of it. Building software is amazing as the barrier is very low and you can iterate and experiment so fast. But 99% of software I've built exists only as 1s and 0s on a hard drive somewhere. There's something great about physically holding something you've built. I mainly built midi controllers for friends and other weird i/o devices, But the fact that (maybe) they are sitting somewhere collecting dust brings me joy.
- lvoudour 9y ago
  I feel the same with any project with "physical" results, from electronics to woodwork to fixing a leaking pipe. Don't know why but I get a fuzzy satisfaction that I never do with software. My previous job involved lots of lab work, soldering, debugging PCB issues, working with optical fibres, et al. Current job pays better and is complex enough, but it's just me sitting behind a screen all day remotely controlling a piece of hardware we just bought from someone else. I highly recommend everyone who's into software or design but never did anything with hardware to spend some time this week building a simple blinking LED project with the Arduino I second that. These days it's very easy to get some hobby projects going in no time and with a very low budget. Arduinos, FPGAs, simple PCB design, it will give you satisfaction and you'll definitely learn lots useful stuff in the process that's not necessarily tangentially related to software
aidos 9y ago
Great projects! I got an Arduino recently and it’s the best £6 I’ve spent in ages. My pet project is building a synth driven from the midi output of my keyboard. As a software person, “real” electronics felt hard to grok. The Arduino has been a dream. You have to learn loads along the way. How do I get audio out? Oh right, what’s PWM? Oh ok, how do these timer things work? But it’s soooo satisfying. Highly recommended!
- camtarn 9y ago
  Would love to read more about that synth project. I'm just embarking on a similar project myself, using a little Cypress PSoC that a friend gave me. I'd like to make something glitchy and lo-fi - halfway between a Monotron Duo and an Atari Punk Console.
  - JaggedNZ 9y ago
    Checkout https://github.com/BleepLabs/Nebulophone https://github.com/BleepLabs/Nebulophone It's not to hard to build and not a bad place to start. The code could be better, some variables are poorly named and has some minor bugs (off-by-one on the wave table lookup?). I did start to clean it up but never got to submitting a pull request before moving onto other projects.
trisimix 9y ago
Armbian sounds like a version of ambian
DanBC 9y ago
If you want to get into electronic tinkering the Kris Cochrane youtube channel is a good palce to start. He only uses hobbyist kit (so really cheap from AliExpress) and he'll teach simple soldering and surface mount soldering. He also walks through building reallly cheap chinese electronic kits. https://www.youtube.com/channel/UCh8JiW2G9yR2v7TwUm04m_g https://www.youtube.com/channel/UCh8JiW2G9yR2v7TwUm04m_g
deleted 9y ago
[deleted]
murkle 9y ago
This blog is excellent, and has a good "what to buy" and some similar projects eg http://www.technoblogy.com/show?WNM http://www.technoblogy.com/show?WNM The ATtiny85 costs around $1 - it's amazing what you can do with it. I've made / adapted quite a few projects from there and other blogs
linker3000 9y ago
Welcome to my weekend! https://imgur.com/a/XxMUY https://imgur.com/a/XxMUY This is an AVR-based pong video game (Grant Searle), modified to work with BBC micro:bits as digital paddles - also operatable from phones via Bluetooth! This is for a STEM/Code Club event at a local school, for a bit of retro-meets-contemporary fun, and a paddle programming challenge - let's try using the micro:bit accelerometers. The breadboarded circuit will be made up on stripboard, but I'll take along the prototype. https://github.com/linker3000/Microbit-TVPong https://github.com/linker3000/Microbit-TVPong
naveen99 9y ago
Just found this YouTube playlist on electronics basics on YouTube: https://www.youtube.com/playlist?list=PLAA9B0175C3E15B47 https://www.youtube.com/playlist?list=PLAA9B0175C3E15B47 the videos from the usaf training are particularly good. Person who made this playlist has a lot of other good ones too.
ilteris 9y ago
I love tinkering with hardware. I just hate the debugging because now you have both physical on top of code debugging you have to deal with in order to find out where things go wrong.
- octorian 9y ago
  But you get to play with lots of cool fancy equipment do to that debugging! (Okay, that equipment is also kinda expensive, and retains its value far longer than old computers... But even new stuff has gotten a lot cheaper than it used to be.)
- joezydeco 9y ago
  Typically on a new hardware design I'll write throwaway code that exercises all outputs. You use this to verify the schematic. Maybe half the time that code evolves into an API/HAL that the final application will use. Many times it also becomes code for manufacturing test (burn in with the test code, then reflash with final production firmware right before boxing) Starting out with application code on top of a brand new design will lead to madness. Take it in smaller steps.
- yoran 9y ago
  This takes me back to the days when I was an embedded software engineer. One day I had to write a Linux driver for a custom piece of hardware the company had developed. I just couldn't get it to work. While trying to understand what was going on, I literally went down the levels of abstraction until I was measuring voltages with an oscilloscope. Turns out that one of the resistors on the board wasn't properly soldered. It was a good journey from software to all the way down to hardware, but frustrating. Nowadays I develop web applications and I'm happy that I don't have to deal with this kind of problem anymore.
Animats 9y ago
After building some electronics [1] I kind of think it's a pain. It took me seven tries to get the switching power supply working right. Can't do that on a prototyping board; layout matters, and all the parts are surface mount. LTSpice simulations get you close, but not quite there. Then I had to learn to surface mount solder, which means working with tweezers under a microscope. I'm not that good at it. People like that design. Others have built more of them. Someone in Australia plans to manufacture a hundred or so. There's enough interest for hobbyists to build it, but not enough for a real production run. [1] https://github.com/John-Nagle/ttyloopdriver https://github.com/John-Nagle/ttyloopdriver (USB interface for old Teletype machines, models from 1910 to 1960).
vkuruthers 9y ago
Does anyone know what kind of circuit would be able to convert 12VDC (e.g. from a small lead acid gel. cell battery) to 20VDC (which my Lenovo E470's DC charging voltage)? The E470 is my work computer and does not have an easily swappable battery, so I wanted to experiment with some kind of external charging system I can use when working remote at sites without accessible outlets.
- htgb 9y ago
  It's called a boost converter (or step-up converter), a specific kind of DC-DC converter. When searching, first look at rated input and output voltages. If the output voltage of a DC-DC converter is a range, verify in the data sheet that it can indeed _boost_ the voltage to whatever you set it to (unless it's specifically called a boost converter or step-up converter).
  - vkuruthers 9y ago
    Thank you sir! I'll do some part searching this week.
- vibrolax 9y ago
  If you want a near turn-key solution, there is this: http://www.mini-box.com/DCDC-USB?sc=8&category=1264 http://www.mini-box.com/DCDC-USB?sc=8&category=1264 Mini-box has a number of dc-dc converters and battery charging systems for gel-cell and other batteries. I do not have personal experience with their products, but I'd try them first if I wanted something other than a hack. For hacks there are tons of boost converter boards on eBay/aliexpress, but these typically don't have chargers, short protection, or other features you might want if you need more robustness
  - vkuruthers 9y ago
    Thanks @vibrolax, that does look ideal. I was going to muck around and design the circuit myself (hopefully based off a solid reference design), but the COTS setup you listed above looks just like what I need, so I think I'll go ahead and get it once funds allow :) Thanks again for the tip.

192 points by ttsiodras 9y ago

I would love to see what tinkering could be done with low-power, minimal or "self-sufficient" location-placement of sensors to gather data and report data using Lora, cdma, or HF for long range. Why? Because electronics are small and there should be interesting ways to exploit the difference between this smallness and full blown CPUs operating on the grid. But I have a hard time generating good ideas. Any thoughts?

draugadrotten 9y ago
I'm with you. Using the Things Network https://www.thethingsnetwork.org/ https://www.thethingsnetwork.org/ I am currently setting up a gateway and connecting a few remote sensors to it. Right now I am just sending simple sensor data (button_press, temperature, light etc) but I would like to expand on this and send other data. For example I want to be able to deploy my own speed traps, measuring vehicle speeds on any road I want. I don't need to connect the speeds to reg plates, so I'm thinking about just measuring when the car passes through an IR beam or measuring a magnetic pulse or similar... Also, air quality monitoring. And of course, the robot lawn mower is getting an upgrade for the spring. Water temperature in the lake might be a good addition for summer. I forgot to say but since it is https://www.thethingsnetwork.org/ https://www.thethingsnetwork.org/ everything I do is already connected to Alexa and IFTTT... imagine waking up in the morning and having Alexa tell you that it is a good day for a morning swim, since the water is X degrees. Yum.
- platz 9y ago
  Those are fantastic ideas - love it!
simonbarker87 9y ago
Making extremely low power consumption nodes is very satisfying, I made a very simple light sensor remote sensor node that could power itself from 50mg of vibration acceleration a few years back on as part of my PhD in energy harvesting. The mast challenging part was getting the pic to draw the absolute minimal current and manage the power draw of all the other systems. The current draw was so low by the end that we had to use an electrometer with a 30 giga ohm (if I remember correctly) input impedance to accurately measure the current draw. Programming in asembly was a pain but I had a lot of help on that so not awful.
- asmithmd1 9y ago
  A high voltage meter input impedance will minimize the meter's effect on the circuit under test when measuring voltage, not current. For accurate current measurements, you want to measure the voltage drop across an accurate, low-value "shunt" resistor that carries all the current for your circuit.
  - simonbarker87 9y ago
    Correct, so we used a high impedance voltage meter across a calibrated resistor in series with the circuit under test. It was 7 years ago I did the work and now rarely work hands on with electronics so I am hazy on the exact details but it’s all in the published journal paper, which, as always with science papers is now behind a paywall. UPDATE: I miss remembered, we used the high impedance electrometer to buffer the input of a National Instruments interface board so we could record the voltage build up across the storage capacitors, if you use a normal voltmeter the caps just discarge into the voltmeter and the charge never builds up enough to allow the micro controller to turn on, run the code it needs to and then go back to sleep. You land up with some really nice sawtooth wave forms with this method and, as the acceleration on the vibrational energy harvester increases, the frequency of the sawtooth changes proportionally up to a point where the system is transmitting all the time.
jerrysievert 9y ago
take a look at the feather m0 from Adafruit - I have a few deployed where wifi is quite a ways away, gathering data for me and sending to another one acting as a base station. I haven't added solar, as these are inside, near power, but have some solar panels and hardware waiting for me to deploy out in the field (literally). so far, it's been my lack of good waterproof enclosures that has slowed me down. I wonder if there'd be a good opportunity for someone in that space.
- Kliment 9y ago
  Put it in one of those sealable jars with hinges - stuff a few packets of dessicant inside to stop condensation and you're done. If you need to pass through wires score a v-shape into the seal and make sure they get squeezed tight when you close the jar. Something like http://img4.foodservicewarehouse.com/Prd/1900SQ/AmericanMetalcraft_HMJ5.jpg http://img4.foodservicewarehouse.com/Prd/1900SQ/AmericanMeta... make sure to get some extra sealing rings if you do passthroughs as it's hard to get the scoring right.
- platz 9y ago
  But what did you use it for
- HeyLaughingBoy 9y ago
  What opportunity do you see? There's a huge variety of different flavors of water-resistant enclosures on the market, from things that can only take light spray, to underwater-rated enclosures. Google IP-66 or NEMA4 enclosures. Also, I have at least one project that was housed in clear 3" PVC pipe since it had to go down a well. One of my favorite companies to work with in this area is Polycase.
abraae 9y ago
I am working on a lora/arduino mesh network for reporting back the state of a large number of traps for invasive predators (mustelids, possums, rats). The traps are spread around the countryside in dense bush/jungle. When one goes off, someone needs to tramp in and clear and reset it. Currently, there is no monitoring of any kind, so checking traps is extremely labour intensive. The trickiest aspect of this project is that each node needs to spend virtually all of its time asleep to minimise battery drain, yet for two nodes in the mesh to communicate, they both need to be awake at the same time. Drifting clocks etc. The easiest aspect is that the acceptable data rate is 1 bit every 8 hours or so!
- icebraining 9y ago
  I'm totally ignorant about radio hardware, but I'm curious, why not use a chip with wake-on-radio?
  - abraae 9y ago
    Good idea, except that wake-on-radio requires the radio to be powered on all the time. Whereas I need to sleep everything except the arduino watchdog.
- vkuruthers 9y ago
  What a cool and useful sounding project! Does LORA handle any of the meshing aspect, or do you have to manage that at the application level? Also what kind of node to node range are you getting from the radios, and when the users install them, how do they know they'll be within range of the next node?
  - abraae 9y ago
    Yeah, it is some fun, wish I had more free time to devote to it. LORA doesn't handle any of the mesh behaviour, I'm doing all of that using LORA just at the send and receive level. The devices I am using are moteinos - a cool arduino lora mashup https://lowpowerlab.com/guide/moteino/ https://lowpowerlab.com/guide/moteino/. I see various ranges from LORA, the environment is steep valleys and dense bush which severely dials back the range, sometimes down to a few hundred meters or even less. At this stage I haven't played around with optimising the LORA settings, but there are bound to be some wins there since the required data rate is so low. Good question about installs, my current plan is that before setting out, the user places that part of the network where they are heading into constant beacon mode. The node can then be installed, knowing there's another node within reach. In practice this should be fine anyway, as the recommended placement for traps for e.g. stoats is every 100 meters or so, so usually there will be other traps within range.
sbr464 9y ago
Are you referring to using something like the particle.io platform?

fairpx 9y ago

I design interfaces for a living, but tinkering with hardware is one of the most satisfying journeys I know. Every now and then, like OP, I play around with different hardware projects. It's amazing how, showing a half-baked hardware project to a friend gets them a lot more exciting than showing them a nicely designed software project. It feels like when you're tinkering with hardware a lot more parts of the brain are challenged and thus generate a more fulfilling experience. I highly recommend everyone who's into software or design but never did anything with hardware to spend some time this week building a simple blinking LED project with the Arduino. You'll know exactly what I'm talking about.

Tade0 9y ago
I guess half of that satisfaction can be attributed to the fact, that hardware - especially analogue - is not as lenient about errors as software. If you burn a transistor you burn a transistor - it's now useless for its original purpose, so you have to triple check everything. Also there are 2nd and 3rd order effects that require experience to catch. Example: I was really happy that my two 555 timers driving some LEDs were synchronized so good until I realized that they were plugged into the same weak power source, so the voltage drop from power surges triggered them both.
- w-ll 9y ago
  I really got into building simple hardware while in college. For me it was about the physical aspect of it. Building software is amazing as the barrier is very low and you can iterate and experiment so fast. But 99% of software I've built exists only as 1s and 0s on a hard drive somewhere. There's something great about physically holding something you've built. I mainly built midi controllers for friends and other weird i/o devices, But the fact that (maybe) they are sitting somewhere collecting dust brings me joy.
lvoudour 9y ago
I feel the same with any project with "physical" results, from electronics to woodwork to fixing a leaking pipe. Don't know why but I get a fuzzy satisfaction that I never do with software. My previous job involved lots of lab work, soldering, debugging PCB issues, working with optical fibres, et al. Current job pays better and is complex enough, but it's just me sitting behind a screen all day remotely controlling a piece of hardware we just bought from someone else. I highly recommend everyone who's into software or design but never did anything with hardware to spend some time this week building a simple blinking LED project with the Arduino I second that. These days it's very easy to get some hobby projects going in no time and with a very low budget. Arduinos, FPGAs, simple PCB design, it will give you satisfaction and you'll definitely learn lots useful stuff in the process that's not necessarily tangentially related to software

aidos 9y ago

Great projects! I got an Arduino recently and it’s the best £6 I’ve spent in ages. My pet project is building a synth driven from the midi output of my keyboard. As a software person, “real” electronics felt hard to grok. The Arduino has been a dream. You have to learn loads along the way. How do I get audio out? Oh right, what’s PWM? Oh ok, how do these timer things work? But it’s soooo satisfying. Highly recommended!

camtarn 9y ago
Would love to read more about that synth project. I'm just embarking on a similar project myself, using a little Cypress PSoC that a friend gave me. I'd like to make something glitchy and lo-fi - halfway between a Monotron Duo and an Atari Punk Console.
- JaggedNZ 9y ago
  Checkout https://github.com/BleepLabs/Nebulophone https://github.com/BleepLabs/Nebulophone It's not to hard to build and not a bad place to start. The code could be better, some variables are poorly named and has some minor bugs (off-by-one on the wave table lookup?). I did start to clean it up but never got to submitting a pull request before moving onto other projects.

trisimix 9y ago

Armbian sounds like a version of ambian

DanBC 9y ago

If you want to get into electronic tinkering the Kris Cochrane youtube channel is a good palce to start. He only uses hobbyist kit (so really cheap from AliExpress) and he'll teach simple soldering and surface mount soldering. He also walks through building reallly cheap chinese electronic kits. https://www.youtube.com/channel/UCh8JiW2G9yR2v7TwUm04m_g https://www.youtube.com/channel/UCh8JiW2G9yR2v7TwUm04m_g

deleted 9y ago

[deleted]

murkle 9y ago

This blog is excellent, and has a good "what to buy" and some similar projects eg http://www.technoblogy.com/show?WNM http://www.technoblogy.com/show?WNM The ATtiny85 costs around $1 - it's amazing what you can do with it. I've made / adapted quite a few projects from there and other blogs

linker3000 9y ago

Welcome to my weekend! https://imgur.com/a/XxMUY https://imgur.com/a/XxMUY This is an AVR-based pong video game (Grant Searle), modified to work with BBC micro:bits as digital paddles - also operatable from phones via Bluetooth! This is for a STEM/Code Club event at a local school, for a bit of retro-meets-contemporary fun, and a paddle programming challenge - let's try using the micro:bit accelerometers. The breadboarded circuit will be made up on stripboard, but I'll take along the prototype. https://github.com/linker3000/Microbit-TVPong https://github.com/linker3000/Microbit-TVPong

naveen99 9y ago

Just found this YouTube playlist on electronics basics on YouTube: https://www.youtube.com/playlist?list=PLAA9B0175C3E15B47 https://www.youtube.com/playlist?list=PLAA9B0175C3E15B47 the videos from the usaf training are particularly good. Person who made this playlist has a lot of other good ones too.

ilteris 9y ago

I love tinkering with hardware. I just hate the debugging because now you have both physical on top of code debugging you have to deal with in order to find out where things go wrong.

octorian 9y ago
But you get to play with lots of cool fancy equipment do to that debugging! (Okay, that equipment is also kinda expensive, and retains its value far longer than old computers... But even new stuff has gotten a lot cheaper than it used to be.)
joezydeco 9y ago
Typically on a new hardware design I'll write throwaway code that exercises all outputs. You use this to verify the schematic. Maybe half the time that code evolves into an API/HAL that the final application will use. Many times it also becomes code for manufacturing test (burn in with the test code, then reflash with final production firmware right before boxing) Starting out with application code on top of a brand new design will lead to madness. Take it in smaller steps.
yoran 9y ago
This takes me back to the days when I was an embedded software engineer. One day I had to write a Linux driver for a custom piece of hardware the company had developed. I just couldn't get it to work. While trying to understand what was going on, I literally went down the levels of abstraction until I was measuring voltages with an oscilloscope. Turns out that one of the resistors on the board wasn't properly soldered. It was a good journey from software to all the way down to hardware, but frustrating. Nowadays I develop web applications and I'm happy that I don't have to deal with this kind of problem anymore.

Animats 9y ago

After building some electronics [1] I kind of think it's a pain. It took me seven tries to get the switching power supply working right. Can't do that on a prototyping board; layout matters, and all the parts are surface mount. LTSpice simulations get you close, but not quite there. Then I had to learn to surface mount solder, which means working with tweezers under a microscope. I'm not that good at it. People like that design. Others have built more of them. Someone in Australia plans to manufacture a hundred or so. There's enough interest for hobbyists to build it, but not enough for a real production run. [1] https://github.com/John-Nagle/ttyloopdriver https://github.com/John-Nagle/ttyloopdriver (USB interface for old Teletype machines, models from 1910 to 1960).

vkuruthers 9y ago

Does anyone know what kind of circuit would be able to convert 12VDC (e.g. from a small lead acid gel. cell battery) to 20VDC (which my Lenovo E470's DC charging voltage)? The E470 is my work computer and does not have an easily swappable battery, so I wanted to experiment with some kind of external charging system I can use when working remote at sites without accessible outlets.

htgb 9y ago
It's called a boost converter (or step-up converter), a specific kind of DC-DC converter. When searching, first look at rated input and output voltages. If the output voltage of a DC-DC converter is a range, verify in the data sheet that it can indeed _boost_ the voltage to whatever you set it to (unless it's specifically called a boost converter or step-up converter).
- vkuruthers 9y ago
  Thank you sir! I'll do some part searching this week.
vibrolax 9y ago
If you want a near turn-key solution, there is this: http://www.mini-box.com/DCDC-USB?sc=8&category=1264 http://www.mini-box.com/DCDC-USB?sc=8&category=1264 Mini-box has a number of dc-dc converters and battery charging systems for gel-cell and other batteries. I do not have personal experience with their products, but I'd try them first if I wanted something other than a hack. For hacks there are tons of boost converter boards on eBay/aliexpress, but these typically don't have chargers, short protection, or other features you might want if you need more robustness
- vkuruthers 9y ago
  Thanks @vibrolax, that does look ideal. I was going to muck around and design the circuit myself (hopefully based off a solid reference design), but the COTS setup you listed above looks just like what I need, so I think I'll go ahead and get it once funds allow :) Thanks again for the tip.