Over Serial Configuration - Sketch 2.1

This article is for sketch RPICT7V1 version 2.1.
Note a web interface page will be develop in a close future.

Preliminaries

To configure the RPIct7V1 (version 2) over serial a serial terminal tool is required. We recommend using simple Linux terminal command (stty, cat, echo).

Two terminal windows will be opened (ssh, putty etc...). One for reading the other for sending commands.

On the first terminal configure the serial like so:

stty -F /dev/ttyS0 raw speed 38400

Then start reading the data from the rpict board:

$ cat /dev/ttyS0

On the second terminal command can be sent to the serial port using the echo command. For example:

$ echo "a_command" > /dev/ttyS0

This will send the command a_command to the serial port.

As the RPICT7V1 continuously send current/power/voltage data at regular intervals we need to interrupt the board first. The "x" command is used for this. This will instruct the rpict7v1 to stop sending data and listen for commands. We will call this the interactive mode.

$ echo "x" > /dev/ttyS0

Command list

The table below shows all available commands.

Command list

Command	Description	Parameters value/range	Example
x	Enter/exit interactive mode.	None	x
print	Prints entire configuration	None	print
polling <interval>	Change the polling interval.	<interval> in seconds in the range 0 to 255.	polling 5
format <f>	Modify the output format.	<f> is 0 or 1. 0: CSV. 1: Emoncms	format 0
id <nodeid>	For Emoncms format only. Modify the Emoncms node ID.	<nodeid> in the range 0 to 255.	id 11
vcal <vcal>	Modify the voltage calibration coefficient.	<vcal> can be any floating point number.	vcal 548.0
ical <ical>	Modify the current calibration coefficient.	<ical> can be any floating point number.	ical 83.33
addnode <current_pin> <slave_pin> <voltage_pin> <slave_pin>	Add an additional node for computing power with a given current/voltage combination. See below for further details on pins number.	<current_pin> and <voltage_pin> must be one of 1,2,3,4,5,6,7,8. <slave_pin> must be one of 10,6,7,8,9.	addnode 8 6 1 10 The above will use current on ct1 on slave1 computed against voltage1 on the master board.
addchannel <combid> <type>	Add an output channel. <comid> is the combination node id calculating the data. Use print to find out. <type> is the type of data (real power, vrms, etc..).	<comid> is a number from 0 to 255. <type> is a number from 0 to 4. 0: None 1: RealPower 2: ApparentPower 3: Vrms 4: Irms	addchannel 0 3 this example add a realpower channel computed from combination id 0.
rmnode	remove the last combination node	None	rmnode
rmchannel	remove the last channel	None	rmchannel
zero	remove all combination nodes and channels	None	zero

A print example

This is an example of what the print command output looks like:

# 
# Polling: 5
# Format: 0
# Emoncms ID: 65
# VCAL: 548.00
# ICAL: 83.33
# Nodes
# id sct sla vol sla
# 0 8 10 1 10
# 1 7 10 1 10
# 2 6 10 1 10
# 3 5 10 1 10
# 4 4 10 1 10
# 5 3 10 1 10
# 6 2 10 1 10
#
# Channels
# n id type
# 0 0 1
# 1 1 1
# 2 2 1
# 3 3 1
# 4 4 1
# 5 5 1
# 6 6 1
# 7 0 4
# 8 1 4
# 9 2 4
# 10 3 4
# 11 4 4
# 12 5 4
# 13 6 4
# 14 0 3

Combination nodes

Combination nodes are small programs in the microcontroller that computes power given a current/voltage couple.

When configuring the board with addnode the four given parameters are the pin numbers where to find the current and voltage and also which slave (or master) is to be used.

For example

addnode 8 6 1 10

will use current ct1 (8) on slave 1 (6) computed against voltage1 (1) on master board (10).

The tables below gives all pin assignment:

current_pin voltage_pin

Pin number	RPICT7V1	RPICT8
1	V1	CT8
2	CT7	CT7
3	CT6	CT6
4	CT5	CT5
5	CT4	CT4
6	CT3	CT3
7	CT2	CT2
8	CT1	CT1

slave master pins

Pin number	Board type
10	Master
6	Slave 1
7	Slave 2
8	Slave 3
9	Slave 4

Channels

We are refering as a channel here a data stream to be sent out. For example Vrms and Realpower derived from a same sensor will be two different channels.

These are configured with the addchannel command. Two numbers must follow. The first one is the combination id defined above. The id is given when issuing a print command. The second number identifies the type of channel. For example:

addchannel 0 3

Add another channel using voltage/current combination node id 0. Channel type 3 which is Vrms as shown in the table below.

The table below shows the convention being used:

code	Channel Type	Description
0	None
1	Real Power	Real Power in Watts
2	Apparent Power	Apparent Power in Watts. This is Irms*Vrms
3	Vrms	Rms Voltage in Volts
4	Irms	Rms current in milliAmps

Using Configuration file

Here is a great feature. All these commands can be saved in a file and executed together using one simple Linux (bash) command.

For example this is the content of a single RPICT7V1 in single board usage configuration file:

x
print
zero
vest 0
addnode 8 10 1 10
addnode 7 10 1 10
addnode 6 10 1 10
addnode 5 10 1 10
addnode 4 10 1 10
addnode 3 10 1 10
addnode 2 10 1 10

addchannel 0 1
addchannel 1 1
addchannel 2 1
addchannel 3 1
addchannel 4 1
addchannel 5 1
addchannel 6 1
addchannel 0 4
addchannel 1 4
addchannel 2 4
addchannel 3 4
addchannel 4 4
addchannel 5 4
addchannel 6 4
addchannel 0 3
print
x

Lets save these commands in a file called 1xrpict7v1.conf. To execute them use the command shown below. Make sure this is done out of interactive mode. i.e. data are being displayed.

$ while read line; do echo $line > /dev/ttyS0; sleep 0.1; done < 1xrpict7v1.conf

If using another configuration only replace the filename 1xrpict7v1.conf as appropriate.

We have preconfigured some usual configurations below and summarised them in a table.

Filename	Description
1xrpict7v1.conf	Single board. 7 channels of realpower. 7 channels of Irms. 1 channel of Vrms.
2xrpict7v1.conf	2 boards. One master and one slave. 1 channel of Vrms. 14 channels of realpower.
5xrpict7v1.conf	5 boards. One master and four slaves. 1 channel of Vrms. 35 channels of realpower.