If you set Z= LOW, SO= HIGH, S1=LOW, S2=LOW, nothing will happen because Z needs to be set HIGH to turn the board on.

If you set Z= HIGH, S0= HIGH, S1=LOW, S2=LOW, the Y1 pin will be energized So as an example, if you set Z= HIGH, S0= LOW, S1=LOW, S2=LOW, the YO pin will be energized. I've included the possible logic states from my code here below: Using three different pin permutations, it is possible to get 8 different outputs. In order to send a control signal from one of the Y Out pins, you need to program the Arduino to do two things:ġ- Set the Z pin to High (This is a basic Off/ On signal to turn the board on)Ģ- Send a specific permutation of High vs Low logic to the S0-S1 pins

My solenoid controllers (MOSFETs) will be hooked up to these pins, allowing me to control 8 solenoids from each multiplexer. The bottom half contains the hookups for all 8 independent I/O signals (Y0-Y7). Apparently, the AltSoftSerial package does a good job using interrupt handling.The top half of the board contains the logic signals from my Arduino (S0, S1, S2), a common Off/ On signal (Z), as well as the connections for Ground and Power (GND and VCC).

This way, I have succeeded in combining the two channels, up to now without signal loss (needs more testing).

if a buffer contains at least one packet, transmit 1 character per iteration to the Serial Tx (the other buffer blocked from transmitting) until a packet (including a SYNC byte and a channel identifier) has been transmitted, then switch transmitting to the other buffer if it has at least a packet of data.

choose one of the buffers for transmission:.

if altSoftSerial.available() then receive one character to a circularBuffer2 including a SYNC marker and a channel identifier.

if Serial.available() then receive one character per iteration to a circularBuffer1.

TxCombined to WiFi module=hardwareUART Tx at 9600Īs receiving a serial signal (determining start bit onset, sampling at suited locations) in 1/9600 sec needs to avoid data loss and leave some computing time, I considered it important to have a compact main loop. Rx from Sensor2=softwareUART Rx on pin 8, at 9600 using the AltSoftSerial package Rx from Sensor1=hardwareUART Rx on pin 0 at 9600 I have two serial sensors, each delivering data packets asynchroneously over its own 9600 baud line (one sensor occupies 60% of UART time, the other 20% of UART time).Īlthough I agree that is is always good to have performant hardware, but in this case, availability of the boards, space limitation in an embedded device and power supply were all restrained.

Serial port multiplexer arduino