This folder contains the STM8 eForth configuration files for a full-featured system that communicates through a half-duplex simulated serial interface but that also provides the words ?RX and TX! for the STM8 UART.
The binary release contains the image DOUBLECOM, which simulates a 2-wire half-duplex communications interface on PD1/SWIM.
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.