F401 Nucleo Espruino Question

I guess someone bought a few and decided to resell them? If they bought them from Seeed or somewhere then I guess they'd have to increase the price so they could make some profit...

I have done a bit of poking around here and come to a few conclusions.

1). On the MB1136 C-01, it has no LSE or HSE on the main chip, no jumper on SB16 (MCO) or SB50 (MCO). The 02 has LSE and the aforementioned jumpers are present.

2). On the C-01, which seems much more readily available, the clock runs at 16mhz by default. On the C-02, it runs at 84mhz.

3). On the C-01, registers show that clock is using the 16mhz HSI. Attempting to get it to use the PLL based on the HSI via poke has succeeded only in locking up the board when I try to kick it over to the PLL.

3). To install the crystal, 5 things need to be installed. The crystal itself, the 2 loading caps (maybe? We don't need them on the Espruino), and two jumpers to the right of C29. I have given up on trying to connect those jumpers for now. I do not think I will be successful unless I have a correctly sized 0-ohm resistor; those pads are very small and right next to eachother - not like the easy-jumpers on the bottom that you can close with a dab of solder.

4). Shorting the two MCO jumpers makes it run at 84mhz, and poke says it's running off the PLL. No crystal need be installed.

5). MCO stands for Microcontroller Clock Output. The two MCO jumpers are in series. Hence, in this case, the clock signal is coming from the other chip (the one used for STLink)!

6). Never ever make a white PCB, unless you want it to look like crap if anyone ever modifies or repairs it.

In any event, I think the external crystals are unnecessary for general use, and a software change to Espruino is unnecessary. If you got a C-01 board, you can "fix" the clock speed by simply shorting the two MCO jumpers on the underside. No parts, any only minimal soldering skill required. You may not even need solder (I was able to short them by pushing around the solder already on the pads with the tip of the iron)