README: add cable note
@@ -32,7 +32,9 @@ See https://github.com/sinara-hw/Stabilizer
* Clone or download this
* Get a recent openocd, a JTAG adapter ("st-link" or some clone) and
- everything connected and permissions setup
+ everything connected and permissions setup. Most
+ [Nucleo](https://www.digikey.de/short/p41h4v) boards have a
+ detachable ST-Link v2 and are cheap.[^swd]
* Get a multiarch `gdb` (or a cross arm gdb and edit `.cargo/config` accordingly)
* Get [rustup](https://rustup.rs/)
* `rustup override add nightly`
@@ -40,6 +42,14 @@ See https://github.com/sinara-hw/Stabilizer
* `openocd -f stabilizer.cfg` and leave it running
* `cargo run --release`
+[^swd]: Build a cable: connect a standard 8 conductor ribbon with the wires numbered
+ `1-8` to the pins on the St-Link v2 single row 2.54mm connector as `647513(82)`
+ (`(i)` marks an unused wire)
+ and to the [1.27mm dual row](https://www.digikey.de/short/p41h0n) on Stabilizer as `657483x2x1`
+ (`x` marks an unused pin, enumeration is standard for dual row, as in the
+ schematic).
+ It's just folding the ribbon between wires `5` and `6`. The signals on the ribbon
+ are then `NRST,TDI,TDO,TCK,TMS,3V3,GND,GND`.
## Protocol
