Le Net du Kermeur
Solar panel interface

This interface allows to control remotely the solar panel system powering the wireless backbone. The interface provide several measures, and can do some drive too (like starting fans ...). It talks with one of the wireless backbone router.

This article was first posted on the this page on the "Net du Kermeur" website

Since March 2013, a newer interface, based on Arduino, is now in use in our network.

Board with an ATMEGA8535 and a 4 relays board (both bought from Futurlec).


Power used on 5V : ~100mA + 30mA per activated relay; 220mA maximum

Functionalities

8 measures points, 4 used for internal use : input power supply, usage supply, 5V powering the logical circuit, temperature measure.
The power usage can be calculated by : ( input power supply - usage supply ) / value of the shunt.

8 Input/Output with 4 used for the relays board.
The 4 relays are used for : 2 for the unballasting of power use, 1 fan driving (when the temperature is too hot), 1 free

The internal clock can be used for command duration or waiting; it will allow to run some stuff at a given time in the next version of the software. The precision isn't very high, the clock need to be re-sync quite often (cf DATE command).

The external interface is a serial connexion : 19200 bauds 8N1, connected to the wireless router (Mikrotik RB433)

LNDK_AVR Program

Program sources for Atmega8535 (GCC/AVR).

Commands

The invite looks like this: "-->". This show the interface is ready to receive a new command. If it doesn't show at the terminal launch, simply enter a cariage return to force the banner display. Commands are case insensitive.

If everything is ok, the command will return a OK, else it return an ERR.

HELP

Due to memory issues, the help isn't integrated anymore, but return this page URL.

VERSION

Return the version of the ATMEGA8535 software (now AVR004 version 0.01).

DEBUG

Switch to the verbose ouput mode

DATE [OFFSET]

Return the date
The system's date must be set before, or it's return the uptime.
Setting the date is done with the DATE nnnnn, where nnnnn is the time in seconds since 01/01/1970 (epoc).

UPTIME

Return the system uptime.

TESTLED

Use the pin 1 of the port B to blink a led with a rate of 1 beat by second. When serial connexion occurs, the blinking speed change.
The LED/PBO jumper need to be on LED position.
This provide a way to check the program is still running and the serial transfert, but of course use a IO.
re-run the command to stop the test.

PORTB 1..8 [ON-OFF [DUREE]]

Toggle the state of the PORTB 1-8 output.
Warning: The OFF state is used for the 0V ouput (active state), ON 5V.

PORTBS

Show the state of PORTB ouputs 1-8.

MODEB [nn]

Show or modify the mode of the port 1-4. By default, they are used in input mode, set to 1 to force in output mode.

RELAIS 1..4 [ON-OFF [DUREE]]

This is for the commands on PORTB 5-8 ON-OFF [TIME]; this ports are used internaly by the relays board.
The ON state is used for the active state of the relay (!= the PORT command)

ADCA 1..8

Analogue conversion on the PORTA 1-8.

ADCAS

Same a ADCA, but return  the list of values for all pins.

WATCH [ nnn Commande | OFF ]

        Run a command RELAIS or PORTS if no command was received during nnn seconds, example:
                WATCH 600 RELAIS 1 ON 10   
                Will activate the relay 1 during 10 second if the system doesn't receive valid command during 10 minutes.

WATCH OFF
Stop the watchdog.

Communication example

---------------------------------------- LNDK_AVR006v0.01 11/2007 ---------------------------------------- -> date Date 2008-05-21 20h 27m 33s OK -> uptime Uptime 118j 6h 53m 02s OK -> adcas ADC 1 : 1 ADC 2 : 0 ADC 3 : 0 ADC 4 : 1 ADC 5 : 533 ADC 6 : 520 ADC 7 : 508 ADC 8 : 291 OK -> dummy ERR

Terminal Emulation

Of course you need a serial port and a serial connexion software to talk with the system (RS232)
Here a short list

OS	Program	Notes
Linux, *BSD	minicom	Automatisation with option --script, example
MacOsX	ZTerm	+ serial adaptor on Mac
Openwrt	microcom (script possible)	+ package setserial (and MAX232 interface on the WRT54GL)
RouterOS	/system serial-terminal serial0 (no script)	From a RouterOS(winbox, ssh, etc ...) console  Automatisation with Perl Expect module
	Telnet on serveur RFC2217 (cf /port remote...)	From a remote host, script Perl Net::Telnet
Windows	Hyperterminal

Hardware integration

The whole system

We can see the solar panels, the case for the battery (white), the case with the solar panel regulator,
the interface described here and a Mikrotik router, 1 patch antennas, and a directionnal SD19.

Cacti Integration