WTI remote power strip

I have a Western Telematics, Inc RPB+ remote power strip. I picked it up on eBay.

It's a power strip with an RS232 port on it.

On the outside:

5 switched AC outlets, individually controllable
Can switch up to 15A on one port, up to 15A for all ports.
9 pin RS232 port (use a null modem cable to connect)
Dip switch for setting baud rate
An LED for each outlet on the front panel to indicate power on state.

Inside it has:

a PIC 16C56 microcontroller, in a socket
5 nice relays and associated drivers to interface to PIC
a 555 timer
an ADM232 on the serial port
a power supply

A PIC 16C56 has:

18 pin DIP
1.5K memory
25 bytes of RAM (whew! takes my breath away!)
1 8-bit timer
It's OTP = one time programmable

To substitute a flash device I could drop in a 16F628A, then I'd get 3.5k of RAM and 224 bytes of RAM. To do that though I'd need to understand what it's doing. Instead I plan on removing the ADM232, and adding an ESP32-Wrover-IE. I can drill a hole in the front panel to fit an external antenna; otherwise no signal will be going through the aluminum case. This will give me WiFi control of 5 devices.

Normal operation

Manual File:Wti power strip.pdf

There are DIP switches to set serial port rate. I keep it at 9600.

From bellman,

minicom --device /dev/ttyS0

The prompt is RPB+>

The menu should come up. If it does not try typing "/S", that gives you status.

Dart

The basic command is "/n ON | OFF | BOOT", where "n" is a port number 1-5.

BOOT powers down, pauses, then powers up.

ESP32 operation

The ESP32 will need to have its UART connected to the UART of the RPB+. It will need to interface (I suppose) to Home Assistant on the WiFi side. I will make it look like one device with 5 power switches. I will ignore the "reboot" feature and just support "on" and "off".

It looks like ESPhome can handle all of this, of course. I am starting to think there is not anything I cannot do with ESPhome. There is a "UART Switch" component that does exactly what I need.