Which wireless microcontroller if size is priority?

For a wearable project, I am looking for a tiny Arduino compatible microcontroller with at least eight I/O pins, and which can be programmed wirelessly.

Critical is size!

For the prototype, power is supplied externally. So Wi-Fi is OK. If the prototype works out fine, and if we want to continue the project, then BLE would be the better option, but really it’s not a priority at the moment.

LilyPad is often used for wearables. You could combine one of those with a Bluefruit EZ-Link to make it wireless programmable via Bluetooth. Programming via Wi-Fi would probably be significantly more difficult than Bluetooth.

dmjlambert: LilyPad is often used for wearables.

I am aware of LilyPad, but it’s 1. way too big, and 2. adding a wireless interface would make it even bigger. Target size is sth. like 1×1 cm², maybe not possible. Anyhow, the smaller the better! If attaching wires requires soldering to small SMD-type pads, then that’s fine.

I don't think you would find programming via wireless small. That part of the requirement would be difficult. So you still need the Bluefruit EZ-Link to make it wireless programmable. The main processor part you can reduce in size, but when you do, the FTDI programming header will not be a direct fit and you would have to solder the wires. I thought for the main processor this looks interesting: https://tinycircuits.com/products/tinylily-mini-processor

Can you do it with an esp8266 ESP12 or ESP14 module? Peripheral selection shits but they're dirt cheap, popular (so lots of info) and fairly small for a full module with most of what it needs to work...

Sound like the Moteino might be the MCU your looking for.

dmjlambert: I don't think you would find programming via wireless small. That part of the requirement would be difficult.

Indeed I’m thinking about droping that requirement for the first iteration of the device…

The main processor part you can reduce in size, but when you do, the FTDI programming header will not be a direct fit and you would have to solder the wires.

Soldering is no problem. There will be lots of soldering anyhow.

I thought for the main processor this looks interesting: https://tinycircuits.com/products/tinylily-mini-processor

Although it could be smaller, and out of the box it is not wireless, it may do the trick for the first iteration. Thanks for the link!

Riva: Sound like the Moteino might be the MCU your looking for.

For my use case, I don’t see an advantage over the TinyLily. Both are not programmable wirelessly without an additional adapter, and the TinyLily is smaller.

DrAzzy: Can you do it with an esp8266 ESP12 or ESP14 module? Peripheral selection shits but they're dirt cheap, popular (so lots of info) and fairly small for a full module with most of what it needs to work...

Can you program an Arduino over the air using these modules? (doubt it)

feklee:

Quote from: DrAzzy on Apr 17, 2016, 08:36 pm

Can you do it with an esp8266 ESP12 or ESP14 module? Peripheral selection shits but they're dirt cheap, popular (so lots of info) and fairly small for a full module with most of what it needs to work...

Can you program an Arduino over the air using these modules? (doubt it)

The NodeMCU ESP8266 boards support a telnet-like capability that allows one to write, store, and execute Lua scripts on the board "over the air". It's not "Arduino", but they can in a sense be programmed remotely. I think they have a larger memory than the bare ESP12, however.

MrMark:
The NodeMCU ESP8266 boards support a telnet-like capability that allows one to write, store, and execute Lua scripts on the board “over the air”.

I like Lua, thanks for the suggestion! Found a datasheet.

feklee: For my use case, I don’t see an advantage over the TinyLily. Both are not programmable wirelessly without an additional adapter, and the TinyLily is smaller.

Not sure what additional adaptor your talking about for the Moteino-r4. It needs a flash memory chip for OTA programming but the chips footprint is part of the PCB so no bigger in size to fit one.

MrMark: ESP8266 boards support a telnet-like capability that allows one to write, store, and execute Lua scripts on the board "over the air". It's not "Arduino", but they can in a sense be programmed remotely.

i can say from personal experience esp can be re-programmed over the air. and they are supported by ardunio ide but not ota. if indeed power consumption is not an issue it is the only candidate so far that fits the bill.

if low power is important then xl7105 or rfm modules with tiny avr tacked on back are next best option. both very long range.

if cost is important then 433mhz ook modules with tiny are it.

all of these not much more than 1cm size.

Ordered two ESP8266 ESP-03 now. They’re tiny, and they have a good number of I/O ports. Running them with Wi-Fi would drain a small battery pretty fast, I was told, but that’s fine. It’s just for proof of concept for now.

I’m looking forward to the ESP32, just wonder why it’s not available yet.

Here you can see all the different variants of the esp8266 http://www.esp8266.com/wiki/doku.php?id=esp8266-module-family.

Whandall: Here you can see all the different variants of the esp8266 http://www.esp8266.com/wiki/doku.php?id=esp8266-module-family.

Thanks for the link. I used the list on Wikipedia, then picked the smallest one with antenna.

For powering the device, a piece of jewelry, I could start with a CR123A connected externally. Eventually, and if the project goes on, then one could try to find a small LiPo battery similar in size to the ESP8266, plus a capacitor to compensate for power spikes.

feklee: I’m looking forward to the ESP32, just wonder why it’s not available yet.

I just backed an ESP32 kickstarter

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