[ChrisOddy]

Originally Posted by ortek_service

I presume you programmed your PIC16F877A, and did have this running, after assembling it?

I see you also used one of those FTDI TTL-232R-5V USB-Serial-UART leads, as we found its standard connector pinout matches that used on those 'CH340G for WEMOS.CC Mini' modules (That we hadn't got any around yet, and seem less-common than ones built onto a USB type A plug-PCB with a different pinout 5-pin header, instead of 6way socket, although are on eBay / Amazon)
- for the pins that are actually required at least, as pin6 (DTR on CH340G-module, but RTS on FTDI TTL-232R), and pin2 (RTS/CTS link-selectable on CH340G module, as they've re-used the FTDI 'standard' RTS pin for DTR, but always CTS on the TTL-232R connector) are not connected on Phil__G's PCB.

Luckily, I've also got one of those FTDI TTL-232R leads in the original 5V-version (I've many more of the 3.3V-levels version, but I'm not sure they will quite work with this PIC16F877 etc. if the Port-E input is configured as a schmitt-input with > 0.8 * 5Vdd as standard - so even-higher than 2/3 * 5Vdd for CMOS - rather than >2V for inputs using TTL-mode).

Programmed the 877A on my TL866CS and yes I've used a 5V FTDI serial to USB and used Putty for a serial client.