[ESP32] New dev board

Discussion and questions about boards that can run MicroPython but don't have a dedicated forum.
Target audience: Everyone interested in running MicroPython on other hardware.
OutoftheBOTS_
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Re: [ESP32] New dev board

Post by OutoftheBOTS_ » Tue Sep 11, 2018 5:04 am

Cool project, looking forward to seeing what developed from it.

If you want to add a RGB LED it would make sense to use a neopixel then it will only require 1 wire to run it instead of 3 wires and 3 timers.

I have personally used these 2020 sized APA102s http://www.neon-world.com/en/product_de ... =61&id=172 on RPi but they have a clock line as well but they r crazy small though. Not sure if you can find classic 1 wire neopixel that small.

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Roberthh
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Re: [ESP32] New dev board

Post by Roberthh » Tue Sep 11, 2018 6:02 am

Just a question: Since the device is low on pins, why does it have GND and V3.3 twice?
Sorry if that was mentioned in the video. I could not listen to it.

seonr
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Re: [ESP32] New dev board

Post by seonr » Tue Sep 11, 2018 7:32 am

[quote=Roberthh post_id=30023 time=1536645725 user_id=601]
Just a question: Since the device is low on pins, why does it have GND and V3.3 twice?
Sorry if that was mentioned in the video. I could not listen to it.
[/quote]

Hey Robert,

Low on pins is subjective right? ;)

My design choice was two fold...
- 13x GPIO is more than most projects require from a small development board in my experience. Most boards being used at this scale have less than 13 like the D1 mini (10x IO)
- I like it when dev boards I use break out power and GND on both sides of the board, so that's what I add to all of mine. It makes it much cleaner when working on a breadboard.

If I ever hear that 13 GPIO is really a restriction it can be looked at, but I honestly feel that there are plenty of other boards in the "bigger form factor space" that can be used instead if someone needed more IO.

Cheers,
Seon
unexpectedmaker.com
Last edited by seonr on Tue Sep 11, 2018 8:01 am, edited 1 time in total.

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Roberthh
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Re: [ESP32] New dev board

Post by Roberthh » Tue Sep 11, 2018 7:49 am

The D1 mini caused me a lot of trouble, when using it in an application, which needed SPI, I2C, and two more I/O's in addition to the RC/TX. Especially since some of the I/O's are these 'special' ones controlling the boot behavior. Not having many analog pins with the ESP32 is definitely not a problem, unless they improve the ADC.

seonr
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Re: [ESP32] New dev board

Post by seonr » Tue Sep 11, 2018 8:00 am

Roberthh wrote:
Tue Sep 11, 2018 7:49 am
The D1 mini caused me a lot of trouble, when using it in an application, which needed SPI, I2C, and two more I/O's in addition to the RC/TX. Especially since some of the I/O's are these 'special' ones controlling the boot behavior. Not having many analog pins with the ESP32 is definitely not a problem, unless they improve the ADC.
Yeah the D1 mini has some weird pins broken out... D0 got me a few weeks ago on a project.

I made sure that all of the IO I broke out on the TinyPICO was all full multipurpose, and I2C and SPI are there too. I didn't breakout RX/TX though... I'd be interested to know what you were using those for? Was it just general SERCOM? Or were you trying to program the board directly?

I'm not sure if MicroPython on the ESP32 supports the GPIO matrix remapping feature of the ESP32, but if it does, you can remap any of the broken out IO to be whatever you need, including RX/TX I think... but I might need Matt to confirm/deny.

BTW, I am not "anti more IO" - I'm just not sure we should be trying to make TinyPICO everything for everyone as that will lead to us never finishing or shipping it :)

Cheers,
Seon
unexpectedmaker.com

loboris
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Re: [ESP32] New dev board

Post by loboris » Wed Sep 12, 2018 7:55 am

@seonr
I think WiFi will not work well with your current board design (the antenna layout!).
Maybe you could use a small (13.1x18x8 mm) ESP32-Micro module (or the shielded version) to avoid antenna problems.
The board would have a simpler design (with maybe more componnents on the bottom side, psRAM chip should fit too).
It would almost be as if having the 4-layer board.

seonr
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Re: [ESP32] New dev board

Post by seonr » Wed Sep 12, 2018 8:23 am

loboris wrote:
Wed Sep 12, 2018 7:55 am
@seonr
I think WiFi will not work well with your current board design (the antenna layout!).
Maybe you could use a small (13.1x18x8 mm) ESP32-Micro module (or the shielded version) to avoid antenna problems.
The board would have a simpler design (with maybe more componnents on the bottom side, psRAM chip should fit too).
It would almost be as if having the 4-layer board.
Hey Boris,

Yup, rev1 has a terrible implementation! But rev1 was never about a good antenna design, that was always going to come in a later revision. Rev1 is about solidifying the rest of the electronics and ensuring the size is good and the component choices are working well. In rev2 will start looking at optimising the antenna network.

This is my first time working at 0402, so I'm taking it all in small steps :-)

I'm not really a fan of turning the TinyPICO into a double sided board (apart from the optional JST connector on the bottom). Adding components on the second side makes assembly super painful for me and it's just not needed for this project. Neither is 4 layers IMHO. I'm not trying to make THE smallest ESP32 board in the world (yet).. just a small one :-)

Cheers,
Seon
unexpectedmaker.com

loboris
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Re: [ESP32] New dev board

Post by loboris » Wed Sep 12, 2018 9:13 am

seonr wrote:
Wed Sep 12, 2018 8:23 am
... Adding components on the second side makes assembly super painful...
I agree. However, if the micro module is used you could place it as the only component on the bottom side and have the full upper side area free for other componnents. That should be easy to assemble.
It's just an idea, I fully respect your design decissions.

seonr
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Re: [ESP32] New dev board

Post by seonr » Wed Sep 12, 2018 9:19 am

loboris wrote:
Wed Sep 12, 2018 9:13 am
seonr wrote:
Wed Sep 12, 2018 8:23 am
... Adding components on the second side makes assembly super painful...
I agree. However, if the micro module is used you could place it as the only component on the bottom side and have the full upper side area free for other componnents. That should be easy to assemble.
It's just an idea, I fully respect your design decissions.
It's something I did actually look at... have you seen the prices of those modules? I can't get them for anything less than $15 each shipped to me here in Australia. That's more than my current BOM cost for the TinyPICO! Ha!

loboris
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Re: [ESP32] New dev board

Post by loboris » Wed Sep 12, 2018 9:41 am

@seonr
The modules are quite expensive, I don't understand why would shipping to Australia be so much higher than to the rest of the world. I've got 10 pieces for 67.4 US$ and FREE SHIPPING (to EU).

Another disign issue I've noticed.
You are routing pin #16 to the board connector. This pin is used as CS for the internal Flash on ESP32-PICO-D4 and cannot be used for anything else.

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