Didj
Uart Boot on the LX
by Moogle on Aug.31, 2010, under Didj, Electronics
Uart boot has now been figured out on the LX
D5 on the lx
by Moogle on Aug.27, 2010, under Didj
here it is for your uart boot enjoyment
Didj vs LX cart diferences
by Moogle on Aug.25, 2010, under Didj, Electronics
looks like the pad thickness has changed from the didj to the lx
Maybe to reduce to the cost per board? Less surface area to plate?
sd pins and cart detect have longer pads now?
before this was only for the power pads
Pad size comparison, same magnification used on the microscope and angle
Speech Synth Reverse Engineered
by Moogle on Aug.12, 2010, under Arduino / AVR, Arduino / AVR, Didj, Electronics
After a ton of probing and trace fallowing I have come up with this schematic :)
M14 is the piggy backed roms only one side of the pins of the chip are used
IC2 is the TM5200
Table of WTF magic
now for power im using this circuit
work fine with my arduino, now to get to coding and building an small amp for the sound out
TI Speech Synch Exploring
by Moogle on Aug.11, 2010, under Didj, Electronics
I acquired a Ti speech synthesizer module today cheep to experiment with :)
According to this old data sheet I found of the speech chip TMS5200.pdf this should be easy to interface to a Didj or arduino!
Oddly there is a second rom chip stacked on top of the original in parallel with all pins soldered to??
So I took the unit apart and removed the connector carefully to reuse it.
cleaned up the pads and lightly filed the board to fit the connector.
then carefully modified the connector so it would slide onto the board better
Next: power and bus management
| 1 | VCC | +5 Volts power supply | 2 | SBE | Low if addr in >9000-94xx (sound port) |
| 3 | RESET* | System reset (active low) | 4 | EXTINT* | External interrupt (active low) |
| 5 | A5 | Address bus, bit 5 | 6 | A10 | Address bus, bit 10 |
| 7 | A4 | Address bus, bit 4 | 8 | A11 | Address bus, bit 11 |
| 9 | DBIN | Active high = read memory | 10 | A3 | Address bus, bit 3 |
| 11 | A12 | Address bus, bit 12 | 12 | READY | Active high = memory is ready |
| 13 | LOAD* | Un mask able interrupt (=> BLWP @>FFFC) | 14 | A8 | Address bus, bit 8 |
| 15 | A13 | Address bus, bit 13 | 16 | A14 | Address bus, bit 14 |
| 17 | A7 | Address bus, bit 7 | 18 | A9 | Address bus, bit 9 |
| 19 | A15 | Address bus, lsb. Also CRU output bit. | 20 | A2 | Address bus, bit 2 |
| 21 | GND | Ground | 22 | CRUCLK* | Inversion of TMS9900 CRUCLOCK pin |
| 23 | GND | Ground | 24 | PHI3* | Inversion of phase 3 clock |
| 25 | GND | Ground | 26 | WE* | Write Enable (derived from TMS9900 WE* pin) |
| 27 | GND | Ground | 28 | MBE* | Active low if addr in >4000-5FFF (card ROMs) |
| 29 | A6 | Address bus, bit 6 | 30 | A1 | Address bus, bit 1 |
| 31 | A0 | Address bus, bit 0 (most significant) | 32 | MEMEN* | Memory access enable (active low) |
| 33 | CRUIN | CRU input bit to TMS9900 | 34 | D7 | Data bus, bit 7 (least significant) |
| 35 | D4 | Data bus, bit 4 | 36 | D6 | Data bus, bit 6 |
| 37 | D0 | Data bus, bit 0 (most significant) | 38 | D5 | Data bus, bit 5 |
| 39 | D2 | Data bus, bit 2 | 40 | D1 | Data bus, bit 1 |
| 41 | IAQ | Interrupt acknowledged by TMS9900 | 42 | D3 | Data bus, bit 3 |
| 43 | VDD | -5 Volts power supply | 44 | AUDIOIN | To sound generator AUDIO IN pin |
Game Boy Advance on the LX!
by Moogle on Aug.10, 2010, under Didj
Yes we now have a working gameboy advance emulator working on the LX!
sound is a bit messed up on some games but its a start!
DJHI hot swapping almost there and DJHI update
by Moogle on Aug.06, 2010, under Didj, Electronics
There was a slight bug found with the resistor used for the card detect pin for the Micro SD card hot swapping.
Originally a 300k resistor was used to pull down the SD_D3 data line.
It was found that this resistance is too high to use and will not allow for proper hot swap detection of the Mirco SD card.
Though some testing it was found that there is a 100k pull up resistor inside the LX that totally throws off the detection resistor value and makes it not work.
The Solution: Replace the 300K resistor (R4) with a 82.5k resistor.
All boards made from today on will feature this new update.
This is what the new resistor looks like
I am trying to figure out how to ship out resistors to those who already purchased a DJHI and would like to try to fix this.
There have also been reports of random shorts and strange behavior when the DJHI is plugged into a LX or Didj. I looked at the boards very closely and found a small routing problem that happens on some boards.
It is some times very very hard to see with the naked eye but under the microscope you can see some debris of the connector from the routing going a little too far. General use of the DJHI can cause this little flake of metal to flatten out and cause a short.
Solution: if you are experiencing random glitches and non power on issues, take a razor blade and CAREFULLY remove the debris from between the ends of the pads. As of today this will be checked for for every board built from now on.
SDL lib compiled for the Didj / LX
by Moogle on Aug.02, 2010, under Didj, Game Programing
if you have the frame buffer installed then this will make your life more easy when it comes to getting graphical things working on your system :)
included are some test programs too :)
Behind the scenes
by Moogle on Jul.30, 2010, under Didj, Electronics
so what is moogle currently working on?
well now that you ask :)
GPS on the LX!!
it is as simple as
modprobe ftdi_sio.ko
and
stty -F /dev/ttyUSB1 raw ispeed 38400 ospeed 38400 -ignpar cs8 -cstopb then
cat /dev/ttyUSB1
and you have the data from the FMP04 GPS module streaming to your terminal :)
now to get gpsd compiled for the LX and the real fun can begin.
the surface has only begun to be scratched ! Arduino mobile development and programming anyone?