Sofirn SC21 mini

jon_slider · June 15, 2022, 3:07pm

for a flashing guide for the SC21 Pro see posts 206 and 209 by Adair21

for a flashing guide to Sofirn SP10 Pro see this post by zumlin

jon_slider · June 16, 2022, 12:50am

tldnr
can someone sell me a pogo harness for SC21 Pro that plugs into my TTL?

Im just in over my head trying to understand this:

Im trying to understand what connections to make to the TTL…

questions:

1. you want me to connect pin 6 on the SC21 to VCC? my TTL does not have a VCC label… which label is equivalent to what you call VCC?

2. you want me to connect pin 1 on the light to Both TX and RX on the TTL? And does this programmer need a resistor between pin 1 on the SC21 and the TX and RX parts of the TTL?

sorry to be dense… if this is just too many questions… I understand. Totally lost here…

Adair21, could you share a photo of the TTL and wiring harness you use to flash SC21 Pro? And how you conect to the light? I think Im a visual learner…

Yngvej · June 17, 2022, 2:22pm

1: Use the 5V pin as VCC.

2: this is how I connected it:
Green goes to tx, blue goes to rx. The orange wire goes to pin 1 on the SC21

github.com

SpenceKonde/AVR-Guidance/blob/master/UPDI/jtag2updi.md

# SerialUPDI
SerialUPDI is a UPDI upload tool which uses a normal USB serial adapter with the most trivial of modifications directly as a UPDI programmer
It was written in 2020-2021 By Spence Konde and Quentin Bolsee based on the pymcuprog tool from Microchip, which is much, much, slower.

## jtag2updi? Never heard of him
This page was formerly dedicated to discussing jtag2updi. jtag2updi was a program written in some of the most inscrutable C++ it has been my misfortune to work with, and it could be loaded onto a wide variety of AVR microcontrollers, and they could then be used as a UPDI programmer. The code was buggy, and very few people could make sense out of it. It's performance was passable, though, for example, Optiboot performed better at uploads, and both Optiboot and jtag2updi were stuck with baud rates 1/4th to 1/3rd of what the chip could be written at.. In late 2020, the first versions of SerialUPDI were created from pymcuprog, but the performance was very disappointing. In mid 2021, a push was undertaken to make it perform better than jtag2updi. The progress and the short time it took to make it exceeded all expectations. Since the 2021 performance sprint, SerialUPDI - which had write speeds as poor as 600b/s at the time this effort was started, advanced very rapidly. Within just a few days, speeds over 10k were achieved and within weeks it was faster than everything else. 
Since then some further performance enhancements, as well as ways to throttle it's performance to make sure it didn't overflow the part's receive buffer while it was writing

SerialUPDI is not perfect, but it's imperfections are small compared to those of jtag2updi, and less-initiated individuals are better able to improve it as compared jtag2updi - particularly as most of SerialUPDI's foibles are almost entirely due simply to it having not gotten enough attention from people who know how to write python - so things that should retry on failure or print error messages instead print stack traces, because something's throwing an exception and I don't know how to catch it. But the low level core that writes to the chip is largely fine. As of 11/21, we are no longer offering support for jtag2updi. The cores still support it, but it is not recommended. I will fix no bugs. If someone else wants to leap into this dumpster fire, by all means go ahead. I choose not to.. The only way that thing could be salvaged involves essentially rewriting it de novo so it wasn't a posterchild for how incomprehensible C++ can get.

## Brief orientation: What is UPDI
UPDI is the interface used for programming all AVR parts released since 2016 (the "modern AVRs") (and debugging, but that's locked behind a proprietary interface that nobody has bothered to reverse engineer, even though you can snoop on the protocol with just a serial adapter and even though the large scale structure of the protocol is known too - c'mon guys, this is gonna be a walk in the park compared to debugwire). Unlike the old ISP interface, which was very SPI like (in fact, It seemed to be SPI with the reset pin used like SS, and a somewhat odd pattern of communication). This time, we have a somewhat more sophistcated interface that we're connecting to (they call it the  Asynchronous System Interface (ASI)), and the communication method is via what looks suspiciously like they put another copy of the UART in, hardwired to always be in LBME (half-duplex single wire), 2 stop bits, even parity, and autobaud enabled and WFB (wait for break) as soon as it initializes. This talks to the ASI, which initially only lets you reset the chip and read the device ID and SIB (system information block). 

To enable the programming or debug modes, a "key" is sent - there are three in the datasheet (programing mode, chip erase which as usual is how you unlock and erase a locked chip, and program USERROW which can be written even while the chip is locked). There is also a debug key, I don't know what it is, but if I had a working debug setup with microchip studio, it should be trivial to recover by snooping on the communications during debugging. I'd also wager that this is the way they configure what pincount a part is (since most of the AVR dies these days get put into 2-3 adjacent 

Because it's basically a UART, and it looks like they simply copied the UART, only pointed it at the ASI. UARTs have 2 bytes of buffer on receive. Since halting for flash halts the CPU - but not the peripherals like the UPDI physical layer - it will buffer two bytes and lose dataon the third; this results in, at the end of the page being written, the programmer having written more bytes than the target received, causing the programming to fail at that point, because the the part is still treating the next command as data to write, and doesn't respond. 


## Wiring the hardware
Briefly, you connect Rx and Tx with either a 4.7k resistor or a small (signal) Schottky diode (band towards Tx). The RX like becomes the UPDI

This file has been truncated. show original

Seems like the adapter in your picture have been modded with a diode between T and R. In that case, just use the RX pin, 5V and GND

jon_slider · June 17, 2022, 2:20pm

very helpful… thanks for the photo

so, this is my SP10 programmer from gchart, showing how I would need to connect it to an SC21:
…

Im unclear about tx/rx… the RX is shown, but where does TX go?
does this mean the SC21 Pro uses 4 wires, while the SP10 Pro uses only 3?

Yngvej · June 17, 2022, 2:25pm

The stuff I did on my breadboard have already been done on your adapter. Notice the small black diode crossing between R and T on the board. This one connects them together.

Just use 3 wires. 5V (VCC), GND and RX (UPDI).

jon_slider · June 17, 2022, 3:41pm

Thank You!

will work up the courage to solder some wires for an SC21 Pro reflash… as soon as I grab a proper hex file

Yngvej · June 17, 2022, 2:42pm

Here’s the file I used.
https://toykeeper.net/torches/fsm/anduril2/anduril.2021-12-13.sofirn-sp36-t1616.hex

Solder on!
Remember to do a factory reset after flashing, because it will have slow ramping until you do.

jon_slider · June 17, 2022, 4:02pm

got the Hex file, thanks!

and thanks for all the coaching, including explaining the T and R little black diode on the TTL that gchart built for SP10 Pro… I think Im almost ready to flash SC21 Pro…

instead of soldering wires to the TTL and the flashing pads on the light, I would like to build a pogo adapter for the SC21 Pro

can anyone here suggest a shopping list and links of what to buy to build a pogo pin harness adapter to fit SC21 Pro…

I have no experience shopping for the connectors and wires needed.

Yngvej · June 17, 2022, 3:05pm

You’re welcome.

It’s very easy soldering. If I were you i would just cut the wires in your picture and solder them to the board.
Why wait for parts when you can get new FW already today?

Just apply a small blob of solder to the pads, then a little on the end of the wire.

Put the cable on top of the pad and touch it with the soldering iron so that it melts together.
That way you don’t have to hold the wire, the tin and the soldering iron at the same time.

You can use a soldering braid to remove the solder from the board afterwards if you like (I just left it there in case I want to flash it again in the future).

jon_slider · June 17, 2022, 10:03pm

thanks for your thoughts. I do not want to destroy the pogo adapter that gchart built for the SP10 Pro… so I wont cut those wires.

I do understand I could just solder wires to the programmer and light… and might do that, but, I have more than one SC21 Pro, so a pogo pin harness for that model, would be better than soldering wires…

in any case, thank you very much for getting me past my hardware wiring questions. Will update when I successfully update my SC21 Pro lights to Anduril 2.

update, with the tremendous help from zumlin on reddit I have moved one step closer… I measured the pads spacing on the SC21 Pro,

and he linked me to a potential 6 pogo pin adapter
I went ahead and ordered the one w 1.27mm spacing…

also want to thank gchart for sending me the SP10 Pro kit, that is shown in the photos.

containerfan · June 17, 2022, 10:22pm

jon_slider, please let us know how that 6 pin adapter works out. I don’t mind soldering pins to boards, but I don’t know anything about board design. I was hoping gchart would throw a design out on Oshpark.

zumlin · June 18, 2022, 3:03am

Hey I am actually on BLF too. I read a lot here but I just don’t post much.

The numbers are a bit off, 1.4mm vs 1.27mm, 7.4mm vs 6.35mm (1.27 x 5). I have actually experienced this in the LT1, the spacing between the pads was a bit bigger than between the pogo pins, and they were not lined up straight either, but I was still able to flash it with a similar flashing adapter.

I hope that they are close enough on the SC21 Pro and I hope you have success flashing it.

jon_slider · June 18, 2022, 3:57am

that is my hope as well

thanks for all your time helping me learn to build a pogo adapter for SC21 Pro

Im finally starting to get the picture… LOL

jon_slider · July 17, 2022, 2:06pm

Questions about Parasitic Drain on the SC21 Pro

can someone with proper tools and skills inform

What is the Parasitic Drain of the button LEDs on Low and on High
What is the Parasitic Drain with the main LED ON at lowest mode, w button light on low?
IS there LVP for the Button light, or Can it overdischarge a battery?

backstory, recent reports on the TS10 show no LVP for button lights, and using High Aux (they are wired as button lights), on that light causes overdischarge.

SammysHP · July 17, 2022, 5:23pm

It is not RGB, but single color aux LED
LVP for single color aux LED is not implemented in official Anduril yet

Thus it will be affected as well, like all Anduril lights with single color aux LED.

jon_slider · July 17, 2022, 5:54pm

thank you,

that is why I am asking what the Parasitic Drain is,
on the Green Button Light on High, of the SC21 Pro.
I want to calculate how many days before Overdischarge.

fwiw, that green button light does not produce a measureable output on my light meter

otoh, the TS10 Red Aux on High, measure 0.2 lumens (and overdischarges within 5 days of 24/7).

fwiw, The Floor output of 1/150 on the main LEDs of the TS10 also measures 0.2 lumens.

Adair21 · July 18, 2022, 12:08am

Hey Jon,

I measured the parasitic drain on my SC21 pro at 2.5mA on high and 100µA on low.

With an 800mAh battery, that’s roughly 13 days on high or a year on low.

jon_slider · July 18, 2022, 12:21am

Thank You!

jon_slider · July 24, 2022, 2:25am

I finally figured out how to reflash Anduril 2 onto the SC21 Pro

the programmer I got from gchart for the SP10 Pro, also works for the SC21 Pro, with a separate harness…

I did not have pogo pins, I soldered the wires to the flashing pads on the driver. The wire harness I used for the SC21 Pro, came from a separate purchase on aliex…
.
all this thanks to Adair21’s post,

plus lots of help from several kind people who coached me privately to install all the software and driver, on my iMac.

jon_slider · August 2, 2022, 5:14pm

Question about battery type

is the Sofirn 16340 Battery an ICR, IMR, or INR chemistry?