UART Mode problems talking to Serial Display

[wingster]

hi folks!

just unboxed my new bus pirate today, great stuff! i updated the bootloader and the firmware to 4.1. i'm really a newbie, but the tutorials are really good, thank you for that!

oh, i'm from germany, so sorry for my english!

here is the info:

Code: [Select]

HiZ>i
Bus Pirate v3
Firmware v4.1 Bootloader v4.1
DEVID:0x0447 REVID:0x3043 (B5)
http://dangerousprototypes.com
HiZ>


as a first test i wanted to talk to a sparkfun serial enabled display (see datasheet here: http://www.sparkfun.com/datasheets/LCD/SerLCD_V2_5.PDF) laying around...

here's what i've done in zterm:

Code: [Select]

ATE1 V1
No mode set, M for mode
HiZ>M
1. HiZ
2. 1-WIRE
3. UART
4. I2C
5. SPI
6. JTAG
7. RAW2WIRE
8. RAW3WIRE
9. PC KEYBOARD
10. LCD
(1) >3
Mode selected
Set serial port speed: (bps)
 1. 300
 2. 1200
 3. 2400
 4. 4800
 5. 9600
 6. 19200
 7. 38400
 8. 57600
 9. 115200
 10. 31250 (MIDI)
(1) >5
Data bits and parity:
 1. 8, NONE *default
 2. 8, EVEN
 3. 8, ODD
 4. 9, NONE
(1) >1
Stop bits:
 1. 1 *default
 2. 2
(1) >1
Receive polarity:
 1. Idle 1 *default
 2. Idle 0
(1) >1
Select output type:
 1. Open drain (H=Hi-Z, L=GND)
 2. Normal (H=3.3V, L=GND)
(1) >2
READY
UART>

but after connecting MOSI to the RX pin of the display all i get is permanent "noise" on the display... is there a problem with the display or i'm totaly wrong trying it this way??? i get the same "noise" (something like "double-pipe"-characters) if i connect the MISO pin to the RX of the display...

one more question (if i ever get that communication up and running...):

the datasheet is also talking about sending some control sequences to the display, i.e. "<control>j" how can i do that with the bus pirate and zterm on my mac?

thank you very much!

greetings from germany

wingster

[Sjaak]

Control chars are easy:

J = 0x2a
ctrl = 0x2A & (~0x20)  (clear bit 6)

so ctrl-j = 0x0a

To send it just type 0x0a and it is send to the right protocol lib.

For the display part:
- is it powered?
- does it understand 3.3v logic TTL?

Í'm suspecting it is powered through a data pin...

[wingster]

thank you for the fast answer!!!

the display is powered with an external 5v power adapter... there 3 pins, vcc, grnd and rx.
the backlight is on and the startup-message appears as mentioned in the datasheet. so with this part everything seems o.k....

bye

wingster

[Sjaak]

Please take also a look at  the pullup tutorials:

http://hackaday.com/2009/07/01/mixed-voltage-interfacing-with-the-bus-pirate/ and http://dangerousprototypes.com/2009/07/27/bus-pirate-practical-guide-to-pull-up-resistors/

Connect +5v to the Vpu input and enable output=HiZ (last question) and let us know the results

[wingster]

o.k., i check the tutorials at the weekend and try it...

the display needs ~60mA at 5V, can the bus pirate handle that?

thx

wingster

[ian]

Yes, up to 150ma per power supply.

[ian]

I had this topic bookmarked. Did you ever get it going? Let me know if there's anything else I can do to help.