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HW startup: A journey from (Arduino) idea to product
- hansc 13y agoLove to hear your feedback and reactions
- graphene 13y agoNice read, thanks for sharing. As an arduino noob, it wasn't clear to me why you need a resonator component, especially since it isn't present in your first schematic? Also, have you given thought to what happens after the battery runs out? Can the battery be replaced by the customer or does the device need to be disposed of?
- hansc 13y agoThanks for your reply. The resonator is shown in the 'Eagle schematic', right in the middle of the picture. The first schematic is just for the moisture sensor. I used it as a crystal to run the ATMEGA. When the battery is gone, you just pop open the enclosure and put in a new CR2032 coin cell battery. You can get those at every gas station or supermarket.
- graphene 13y agoPlease bear with me, I'm new to Arduinos/uCs.. So an ATMEGA uC needs an external oscillator to run? Is it to provide the clock signal or for something else? If so, why doesn't it have its own clock signal generator? Wouldn't it always need one to run at all?
- hansc 13y agoThe standard bootloader needs a resonator or crystal to run the oscillator. You can also program a bootloader which uses the internal oscillator in the Arduino IDE, in that case no resonator or crystal is used, like I did with the attiny.
- coob 13y agoSafari 7.0 on OS X 10.9 - I can't add a pre order to my cart! The green circle flies up but the cart remains at 0. Works fine in Chrome. Edit: Also can't check out in Chrome… just sits in 'Completeing Order'
- pedalpete 13y agoGreat write-up, but I have a few questions 1) don't different plants need different amount of moisture in the soil? How do you account for that? 2) why does moistly check the moisture levels so frequently? Wouldn't hourly or even daily be more than enough? I assume partly you are checking regularly because the alarm shouldn't go off after you've done the watering, but what about checking regularly if the last check was 'dry', but not as regularly if the last check was 'wet'?
- hansc 13y agoThanks for the nice comment. To answer your question: 1) Yes, they do. But by measuring the moisture in the soil, you will get an alarm when a certain amount of water is extracted from the soil, being caused by heat, sun or a thirsty plant. After quite a bit of experimentation, we found a threshold value that works for most plants. Not cactuses ;) 2) Indeed we check more often than needed. But if the plant is getting dry, we want to briefly signal every five minutes and before we do that, we do a quick soil check.
- hclee 13y agoThis is really inspiring. When choosing most optimized parts, is there a better way than parametric search in catalogue like Mouser, Digikey or something??