This folder contains a full-featured STM8 eForth configuration for an STM8S "Low density" device like the STM8S103F3P6 that communicates through a half-duplex simulated serial interface but that also provides the words ?RX and TX! for the STM8 UART hardware that are independent of the Forth console. The binary release contains the image DOUBLECOM simulates a 2-wire half-duplex communications interface on PD1/SWIM.
The condiguration is a good starting point for developing simple RS232 protocols in Forth, especially with boards like the C0135, and it's an example for "advanced" serial interface configuration in STM8 eForth.
Please refer to the local globconf.inc for details.
The recommended circuit for connection to a USB RS232 "TTL" adapter is this:
STM8 device . .----o serial TxD "TTL"
. | (e.g. "PL2303" USB serial converter)
. ---
. / \ 1N4148
. ---
ICP header . |
. *----o serial RxD "TTL
. |
STM8 PD1/SWIM-->>-----*----o ST-LINK SWIM
.
NRST----------->>----------o ST-LINK NRST
.
GND------------>>-----*----o ST-LINK GND
. |
................ .----o serial GND
e4thcom fully supports STM8EF 2 wire connections, and an example picocom configuration for half-duplex communication is described here.