This is an old revision of the document!

wCoreF4 PCB

This is the carrier board for the Waveshare Core407v. It performs breakout functions of all of the standard ports as per the design based on the STM32 Discovery.

Schematic

The circuit is mostly identical to what was drawn previously. The following parts are different:

USB entry (J1)

This header supplies +5V, 0V, USB data and the ID state. Normally it will be connected to the USB module by a short cable.

Extended port (J16E)

The original J16 functionality is preserved, but extra pins are available on an IDC16 header. These include the Reset signal and pins normally controlling LEDs. This header is normally connected to the RES-SD module.

User button (JPA0)

This jumper replaces the “bootloader” functionality of the Discovery board's blue button. It could be wired to an external panel control if needed.

BOM v1.0

Type	Qty	Value	Package	Parts	Mouser	Notes
Resistors
	2	220R 5%	THT	R7A, R8A
	2	220R 5%	1206	R7B, R8B
	1	330R 5%	THT	R102
	4	1k 5%	1206	R7B1-4
	2	1k 5%	THT	R11, R13
	1	10k 5%	THT	R12
	1	220k 5%	THT	R101
Pots
	2	10k	6*5mm vert	P1, P2
Capacitors
	3	100n	1206	C1A, C1B, C2
Diodes
	1	1N4148	THT	as marked
Transistors
	1	BC337	TO-92	T1
ICs
	2	74HCT125	SOIC	IC1A, IC1B	595-SN74HCT125DR	Ensure HCT
	1	74HC595	SOIC	IC2
Headers
	2	1*2	male
	1	1*3	male
	1	1*5	male	J1		or wire directly
	9	2*5	male
	3	2*8	male
	2	2*25	female
Hardware
	4		M3 spacer	8mm(?)
MCU breakout
	1	Waveshare Core 407v

Versions

v1.0: first release.

Assembly

The following build order is suggested:

R7B1-4 (1k) and located near J15_S on the top side
R7B and R8B (220R) on the bottom side
C1A, C1B and C2 on the bottom side
IC1A, IC1B and IC2 on the bottom side
Top-side THT components
Bottom-side THT components
Bottom-side JPA0 header
Bottom-side 2*25 pin female headers
Top-side male headers, except for J1
Solder J1 in conjunction with the USB module
Mounting brackets if needed

Connecting the Core407v breakout

Checking the Waveshare board, you will see that there is a real-time clock crystal and associated caps connected across PC14 and PC15. I think it's best to remove these parts so they don't interfere with normal operation. Clip the leads of the crystal and desolder the part if you like. The caps should come off quite easily with a soldering iron tip heating both pads.

Looking at the top side of the PCB (with all headers etc.) and J1 at the “northern” edge, the Core 407v board plugs in on the bottom side with the JTAG header towards the right
Remove the OTG jumpers “FLG,” “VBUS” and “PWR OUT.” USB won't work properly with these closed.
I believe that the correct state of the BOOT CONFIG switch should be set to “SYSTEM”
There's another switch to select the +5V power. It should be set to “USB” when flashing the board using the USB mini connector as a power source, but for our purposes set it to “PWR 5V”.

MIDIbox

Table of Contents