Sparkfun Edge bootloader problems

This is what worked for me: (source: github.com/sparkfun/SparkFun_Edge_BSP/issues/3, the SparkFunEdge tutorial and my teammates!). I am running this on a Linux machine (x86_64; Run $ uname -a) and my SparkfunEdge DEVICENAME=/dev/ttyUSB0

The tutorial does warn you about this problem at Step 4:

Note: Some users have reported issues with their operating system's default drivers for programmer, so we recommend installing the driver before you continue.

Click on the driver link and follow the instructions under "Other Linux distributions" as follows:

1. Install the correct version of the ch34 library. $ git clone https://github.com/juliagoda/CH341SER.git $ cd CH341SER/ $ make $ sudo insmod ch34x.ko $ sudo rmmod ch341

2. To verify that the correct driver is being used, run: $ dmesg .. [889247.585301] usb 1-7: ch341-uart converter now attached to ttyUSB0 [955698.718839] usbcore: registered new interface driver ch34x [955698.718848] usbserial: USB Serial support registered for ch34x [955759.196437] usbserial: USB Serial deregistering driver ch341-uart [955759.196576] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0 [955759.196601] usbcore: deregistering interface driver ch341 [955759.196643] ch341 1-7:1.0: device disconnected

   Now unplug the USB-C from the SparkfunEdge Board, and plug it back again $ dmesg .... [955876.176950] ch34x 1-7:1.0: ch34x converter detected [955876.177320] usb 1-7: ch34x converter now attached to ttyUSB0

glad to hear that you're so excited about the board. I have a hunch that this will be an easy fix.

The Edge boards handed out at the conference have a bootloader set for 115200 baud, however the Edge boards that have come out in the second batch are upgraded to flash at 921600 baud, greatly reducing flashing time. Try changing the baud rate in your serial upload script.

You can also set up the Ambiq Software Development Kit to write your own applications for the Apollo3 microcontroller. Check out the tutorial here: Using the Edge Board with Ambiq SDK

Since I can't comment on your post (not enough reputation.... thanks SE) I'll be responding here.

If the baud rate accuracy is a problem I'm slightly unsure that that would be caused by the OS, but rather I'd think it is a problem with the USB-serial converter chip. I've been using the CH340G whereas on the USB-C version there is the CH340C IC. The difference between the two is that the "C" version includes an internal oscillator to provide the frequency reference. It is possible that that one is less accurate...? I'll try it out over here (but on windows) and let you know.

If this is a persisting problem would you mind making a post on the SparkFun forums? That way our tech support can get linked in (they are the people who could get you replacement hardware in case it is defective, also). Here's a forum for the Edge: SparkFun Edge Forums

If the problem is coming from the OS then the only fix that we can do with the Edge is to reduce the bootloader speed. We're working on a short tutorial about how to do that, but it would require having a programmer/debugger for Cortex-M processors. The Ambiq Apollo3 Evaluation Board has a built-in SEGGER J-Link which is what we used to program the boards.

On MacOS Mojave, Installing/Reinstalling CH340 works for me: https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers#mac-osx

Before doing install, check that you actually see the sparkfun edge device with: ls -l /dev/cu* If driver is correctly installed, you should detect: /dev/cu.wchusbserial1420

I got similar issue whereas I only had /dev/cu.usbserial-1420 and thought that was expected device to access, whereas it is /dev/cu.wchusbserial1420 which was only detected after installed ch340 driver. Then flashing device works successfully for me.