HW startup: A journey from (Arduino) idea to product

http://hwstartup.wordpress.com/2013/09/27/moistly-the-journey-from-arduino-idea-to-product/

by hansc • 13 years ago

14 13 13 years ago

hwstartup.wordpress.com

hansc6• 13 years ago

Love to hear your feedback and reactions

graphene2• 13 years ago

Nice 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?

hansc6• 13 years ago

Thanks 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.

coob• 13 years ago

Safari 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'

hansc6• 13 years ago

Thanks for the feedback! We use shopify, will contact them about it.

pedalpete• 13 years ago

Great 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'?

hansc6• 13 years ago

Thanks 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.

hclee2• 13 years ago

This is really inspiring. When choosing most optimized parts, is there a better way than parametric search in catalogue like Mouser, Digikey or something??

hansc6• 13 years ago

Typically I start with parts that are much used in Arduino projects. Then I move to Digikey, etc and look for good pricing AND plenty of stock and multiple vendors. This helps avoiding component related delays.

hclee2• 13 years ago

Great advice. I will keep that in mind. Thanks

HW startup: A journey from (Arduino) idea to product

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