Hello...

Last summer I bought one of Eagle Tree's Micro Power E-Loggers. With it I also bought the LCD Power Panel which I used playing with the E-Logger on the bench. Now I have the logger mounted in my Corona and the Power Panel sits in the box.

I'm starting to play with programming PIC's and wondering if anyone has any information on the protocol this little LCD display is using thinking maybe I could use it with my PIC's. I did email EagleTree support but have not heard back from them yet.

Anyhow, just thought I'd ask.

tnx
George

I looked at the website for the logger and it looks like the power panel uses four wires. Plus and minus power are two and the other two could be for an I2C interface (SDA, SCL). It could also be a serial interface, but I would bet on the I2C. If you have a scope you could try capture the data from the logger and possibly tell by that what's going on.

Richard...

I have a Fluke digital scope at work I think I'll bring home this weekend and take a look at it. It's a cute little LCD display and would like to use it in some PIC projects if I could. I just thought maybe some one had already interfaced to it and save me from re-inventing the wheel as it were.

tnx agn

George

If you are familar with I2C then it will be obvious what you see on the scope. You really need a two cahnnel scope so you can see what is happening on the two lines that are not + and - . The SCL line wil be a nice sqaure wave that clocks the data in to the lcd and the SDA will be the data. You can actually read the binary value of the data. Let us now how it goes.

In reading thru information in the PIC's, and in mikroBasic I have seen references to I2C but know nothing about it. I will do some reading on it and using the scope (which is a dual trace) I'll try to figure out if that is what this LCD is using. You are right, it does use a 4 wire inteconnect. It is interesting in that the small board soldered to the LCD pins does not appear to have any interfacing IC that I can see, just a few SM capacitors and a diode.

George

Originally Posted by GeorgeP

It is interesting in that the small board soldered to the LCD pins does not appear to have any interfacing IC that I can see, just a few SM capacitors and a diode.

George

probably has the chip die mounted directly to the glass like these: http://www.lcd-module.de/eng/dog/dog.htm

these are also a bit cheaper at around $8 each and come in 3x16 and 1x8 in addition to the standard 2x16 format.

would be nice to know if the eagletree lcd is an off the shelf item or custom made for them.....maybe you can peel the sticker off?



dave

Originally Posted by ZAGNUT

these are also a bit cheaper at around $8 each and come in 3x16 and 1x8 in addition to the standard 2x16 format.

would be nice to know if the eagletree lcd is an off the shelf item or custom made for them.....maybe you can peel the sticker off?

dave

Well, I like the way the PowerPanel is packaged, and I'm not trying to find a cheaper replacement for it, so I'm not going to take it apart. I will continue the try and figure out a way to communicate with it for use in my other projects, but it works so well with the E-Logger that it will still be the primary use of the display.

Hello..
this my first post to this forum but I read this forum from many time...
I'm trying to build a simple telemetry sistem using serial transmitter/receiver ER400TRS connected on the micropower powerpanel pins and another ER400TRS connected to powerpanal Lcd.
Could be a good idea?
I'm not an electronic expert (I'm an it programmer with RC plane hobby and i'm starting with electronic and pic programming) but I'm very interested to this thread because I have some problem to understending the powerpanel LCD electronic protocol to build the right interface, I2C or Serial?

Do you think I Could see the I2C or Serial signal from home made pc Microphone Scope?

Now, I'm building with a max232 an interface I2C to rs232 to analyze the protocol with a serial port sniffer....

I hope to find something intersting...


Emiliano

Originally Posted by schiorro

Hello..
this my first post to this forum but I read this forum from many time...
I'm trying to build a simple telemetry sistem using serial transmitter/receiver ER400TRS connected on the micropower powerpanel pins and another ER400TRS connected to powerpanal Lcd.
Could be a good idea?
I'm not an electronic expert (I'm an it programmer with RC plane hobby and i'm starting with electronic and pic programming) but I'm very interested to this thread because I have some problem to understending the powerpanel LCD electronic protocol to build the right interface, I2C or Serial?

Do you think I Could see the I2C or Serial signal from home made pc Microphone Scope?

Now, I'm building with a max232 an interface I2C to rs232 to analyze the protocol with a serial port sniffer....

I hope to find something intersting...


Emiliano

That would be a very encouraging DIY subject

Any hints about the protocol used ?

Originally Posted by schiorro

... Do you think I Could see the I2C or Serial signal from home made pc Microphone Scope?

Now, I'm building with a max232 an interface I2C to rs232 to analyze the protocol with a serial port sniffer....

I hope to find something intersting...


Emiliano

There is an interesting USB Oscilloscope that also analyzes SPI, I2C, RS232, and 1-Wire protocols:

http://www.circuit-ed.com/PoScope-Ba...zer-P97C5.aspx

Originally Posted by schiorro

Do you think I Could see the I2C or Serial signal from home made pc Microphone Scope?

I2C is either 100KHZ or 400KHZ (low or high speed mode) so there is no way you can process that with a microphone scope (I assume you mean one of those working from a sound card).

I have tried to connect a pic with i2c slave (with 0X address) interface to the micropower but there isn't communication, may be olso because i don't know the i2c slave address of the powerpanel display.

There is a lot of new sensor, memory expander, altitude sensor, all connected together to the same micropower port, so the protocol may be multi slave.

I think that the problem is the i2c slave address of the of the Powerpanel, becouse I read the pdf of the pic istalled in the micropower and it have a i2c master/slave port.

I continue to try to find something intersting.

Bye
Emiliano

The only way to find out, IMHO is to rev engineer the bus when the micropower is connected and working with the LCD, to see what is the signal.

I had a look with a scope today. I understand it is I2C (from a very reliable source).
There are four pins. Starting from the red wire side they seem to be:

1. +5V
2. Ground
3. SDA
4. SCK

The clock line is just bursts of clock in 4 groups and looks like a 2uS clock pulses (250kHz). The SDA appears synced with the clock as you would expect.

When the display is disconnected, a brief clock burst of only 9 transitions appears every few hundred milliseconds, so it seems to handshake with the display.

Cheers,

Glenn.