nRF5 action!
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Just realizing that if I'm going to hand patch the 4 SWD wires onto the board anyway, then I really don't need an SWD block. Consequently, I'm now thinking the Hackaday guy had the right idea with making his entire node the width of a USB connector:
@NeverDie said in Minimalist SAMD21 TQFP32 Pro Mini:
Just realizing that if I'm going to hand patch the 4 SWD wires onto the board anyway, then I really don't need an SWD block. Consequently, I'm now thinking the Hackaday guy had the right idea with making his entire node the width of a USB connector:
I notice that the Hackaday guy's labeling of D- and D+ as pins 28 and 29 conflicts with what Sparkfun has. Sparkfun has those as pins PA24 and PA25 respectively. Is he wrong? I know from direct experience that the Sparkfun board works, so for now I'm going with the Sparkfun pin mapping.
I hear that the PIC MCU chips have a switching fabric that allows you to map any logical pin to any physical pin. I wish the Atmel chips had that. Do maybe these ARM chips have some of that as well?
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yes it depends what ARM mcu you use, some have more freedom regarding pin mapping and peripherals, but atsam can do that too. Very useful.
There are some rules for atsam how to change the mapping for spi or other periph, versus arduino core files and datasheet. But if you don't want to dig in that, you can just follow a mapping from a board which already exists in Board manager. -
I finished the first pass, and it looks as though everything will fit:
A bit more work to do, but this is the approximate form it would take.
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@Terrence said in Minimalist SAMD21 TQFP32 Pro Mini:
@NeverDie NRF or RFM?
Neither. This is just the MCU. If I can get it to run blink, then as a next step I'll add a radio.
It's basically a subset of the sparkfun board, but in a different form factor, with a different USB, and all in 2-layer rather than 4-layer. This will be my first ARM board, so I'm just trying to keep it as simple as possible. The razzmatazz can come later.
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I polished up the USB and re-positioned the headers so they'd fit on a breadboard:
The irony is: after having done all that, I can now more clearly see that it's just not a very efficient form factor. I think for future versions I'll make it not so narrow.
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I polished up the USB and re-positioned the headers so they'd fit on a breadboard:
The irony is: after having done all that, I can now more clearly see that it's just not a very efficient form factor. I think for future versions I'll make it not so narrow.
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I just now sent this to OSH Park:
to see whether or not it works. I still don't know how many uH are the value for the one inductor that Sparkfun used though. Any guesses?@NeverDie said in Minimalist SAMD21 TQFP32 Pro Mini:
I still don't know how many uH are the value for the one inductor that Sparkfun used though. Any guesses?
I see no inductor on Sparkfun's schematic ? Only a 30 Ohm ferrite bead.
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@NeverDie said in Minimalist SAMD21 TQFP32 Pro Mini:
I still don't know how many uH are the value for the one inductor that Sparkfun used though. Any guesses?
I see no inductor on Sparkfun's schematic ? Only a 30 Ohm ferrite bead.
Thanks! I guessing this part should do the business then: https://www.digikey.com/product-detail/en/wurth-electronics-inc/742792601/732-4659-1-ND/4310409
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Argh. For only a little more than what I paid for the Sparkfun SamD21, I couldn't have gotten the same MCU with an RFM69HCW! And it's already on a 2-layer board, not a 4-layer board:
https://www.adafruit.com/product/3176
https://www.amazon.com/Adafruit-Feather-RFM69HCW-Packet-Radio/dp/B01K62LWBC/ref=sr_1_1?ie=UTF8&qid=1497022595&sr=8-1&keywords=Adafruit+Feather+M0+RFM69HCW<insert facepalm icon> I should have started with that instead, because that's already probably close to what I'll end up with.
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It's a very good price. If you do it yourself you have a 3$ MCU, 3$+ radio, 1$ PCB and a few US$ for other components (like lipo charger). Leaving only 10$ left for assembly but if you do it yourself you need a lot of time even with a stencil.
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And believe it or not, the LoRa version can be had for as little as $15.99 each with Prime delivery:
https://www.amazon.com/gp/product/B01LHTU14W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1Yeah, at that price I think this becomes a buy, not build, decision.
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And believe it or not, the LoRa version can be had for as little as $15.99 each with Prime delivery:
https://www.amazon.com/gp/product/B01LHTU14W/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1Yeah, at that price I think this becomes a buy, not build, decision.
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if i remember well, the adafruit board is SAMD21G.
Here another example, sort of feather i made a while for testing SAMD21E. The same it's rechargeable, and I added some features like a rgb led, sma connector for RFM69/95, flash, signing, MYSX etc..
mounted with a weather extension board i made. If there is an interest, i can clean a bit my files and upload it, it's working well ;) -
if i remember well, the adafruit board is SAMD21G.
Here another example, sort of feather i made a while for testing SAMD21E. The same it's rechargeable, and I added some features like a rgb led, sma connector for RFM69/95, flash, signing, MYSX etc..
mounted with a weather extension board i made. If there is an interest, i can clean a bit my files and upload it, it's working well ;) -
if i remember well, the adafruit board is SAMD21G.
Here another example, sort of feather i made a while for testing SAMD21E. The same it's rechargeable, and I added some features like a rgb led, sma connector for RFM69/95, flash, signing, MYSX etc..
mounted with a weather extension board i made. If there is an interest, i can clean a bit my files and upload it, it's working well ;) -
Argh. For only a little more than what I paid for the Sparkfun SamD21, I couldn't have gotten the same MCU with an RFM69HCW! And it's already on a 2-layer board, not a 4-layer board:
https://www.adafruit.com/product/3176
https://www.amazon.com/Adafruit-Feather-RFM69HCW-Packet-Radio/dp/B01K62LWBC/ref=sr_1_1?ie=UTF8&qid=1497022595&sr=8-1&keywords=Adafruit+Feather+M0+RFM69HCW<insert facepalm icon> I should have started with that instead, because that's already probably close to what I'll end up with.
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@NeverDie @Nca78 oki noted!
@Terrence yeah, agree too. i have assembled one for testing as it was new and not available. Unfortunately, regarding Mysensors use, there are no flash for ota (in case for future), no signing, no eeprom for routing table (atsam has no eeprom, only emulation if i remember), no sma connector ... -
@NeverDie I love the Feather boards. Currently working with the RFM69 feather. Build in battery connector/charger is very nice to have.
@Terrence said in Minimalist SAMD21 TQFP32 Pro Mini:
@NeverDie I love the Feather boards. Currently working with the RFM69 feather. Build in battery connector/charger is very nice to have.
Good to hear! :) I ordered one today (after my posting above). There's a good chance I'll receive it on Sunday. I look forward to trying it out.
