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• Starting with esp-idf-v2.0

  davedarko • 06/16/2017 at 20:23 • 0 comments

  http://esp-idf.readthedocs.io/

  Finally found the time and inspiration to work on this project again. To get the I2S demo of CNLohr working, I also needed to be able to compile with the esp-idf.

• celebrations are in order

  davedarko • 05/14/2017 at 21:37 • 3 comments

  http://hackaday.com/2017/05/14/hackaday-prize-entry-wifi-game-boy-cartridge/

  
  I feel some questions are coming my way, so I've updated the detail section :)
  

• precognition in a game boy?

  davedarko • 05/13/2017 at 12:24 • 3 comments

  So I thought to myself, if the ESP is too slow, but the query itself is taking microseconds instead of nanoseconds: why not trick the ESP and spit out the next in array? here's what I got, admittedly one of the better results, but you can finally read something! I can live with it, if I can get it to work reliably.

  

• i2s for parallel IN / OUT?

  davedarko • 05/12/2017 at 23:14 • 1 comment

  https://www.esp32.com/viewtopic.php?f=19&t=1746&p=8153&hilit=parallel#p8153

  Seems like I'm 3us late with reading and preparing my response. The posted scan looks like it takes 175us from address change to address change. Putting it in relation, an EEPROM takes 150ns to respond, that's 1/20 of the time I have now. With 240MHz the ESP32 should have a clock cycle time of 4.16ns. Whaaaat? My math is broken. Seems like the maximum speed for gpios on the ESP is "quite" limited, max toggle freq is around 4MHz. https://www.esp32.com/viewtopic.php?f=2&t=1595&p=7482&hilit=parallel#p7482

  Seems like there is a multipin IS2 interface that was also used on https://github.com/igrr/esp32-cam-demo/blob/master/components/camera/camera.c#L314

  https://www.esp32.com/viewtopic.php?f=12&t=951&p=4113&hilit=parallel#p4113
  

• moar research.

  davedarko • 05/12/2017 at 18:48 • 0 comments

  So from far away it looks alright! I checked every byte and the data is correct. But...

  Look a bit closer and you see this:

  

  It might make sense to give the ESP the control over the OE of the data pins, since it's not fast enough to react to every change on the fly, it might needs better timing.

• Needs moar research

  davedarko • 05/04/2017 at 22:05 • 1 comment

  I can't believe that I'm so close already... but I do need to check the timings and need to find out if I can advance the code more. This needs to be connected to an analyzer.

  

• Hardware setup

  davedarko • 05/01/2017 at 20:52 • 0 comments

  I'm still missing some cables, but so far it is looking quite interesting. I've recycled a donor board, replaced the missing switch with a wire, supply the game boy off of the 3V3 power of the esp board through a diode and soldered 32 cables to the missing cartridge port.

  

• what a week - no end in sight

  davedarko • 04/22/2017 at 19:37 • 3 comments

  The whole week was filled with work - taking support calls, fixing bugs, meetings and more support calls. In between all that we tried to develop the important stuff. Yesterday, after work, I prepared my room for some dry wall construction ,to close the window between my room and the kitchen. Today I was mainly helping my father to build up the dry wall. The next few days I will be painting, letting it dry, glue on wallpaper, letting it dry, putting paint on the wallpaper and letting it dry as well. To make the Wohngemeinschaft great again. My bed is right next to the wall, before the wall I was awake when my roommate was. I need to fix up the light switch as well - I see a Wemos D1 mini soon hanging there too :)

  ---

  Anyways. Back to the project - I received all the parts to get prototyping started and I'm excited to begin, as soon as I can possibly do, but not today - I'm tired. Funding looks great, e-begging works :D

• getting closer to a layout

  davedarko • 04/19/2017 at 20:54 • 0 comments

  I was able to drop a 74LVC8T245 level converter and connect the address pins. A15 on the Game Boy is basically the "chip select" for the ROM / cartridge, when pulled down, since the address space of the 32kb is 0x0000 to 0x7FFF. SO I use that for the output enable pin on the lvl converter.

  The Game Boy write pin will define the direction of the data pins lvl converter. The address lines will be pulled low, meaning the direction is always B->A. I use the pin that was previously the A15 pin to tell the ESP the direction of the communication.

  A0-A3 are connected to input only pins of the ESP. Not unlike the ESP12F there are some pins that are connected to the SPI flash on the module and shall not be connected otherwise.

  So far I only have the RX and TX pin free, but I consider to have the RST line on a transistor - maybe I need to hold the game boy in a reset state for a while, for the ESP32 to boot up and set all pins.

  Not on the picture is the current power supply. I'm a bit worried about the two AAA / LR03 batteries in my Game Boy pocket, they're not that powerful in general and with the LED backlight it's not better. Drawing from the 5V switch mode to convert to up to 250mA will be a challenge. I might need to add a LiPo and/or some tantalum capacitors to make it work.

  

• stuff ordered

  davedarko • 04/19/2017 at 07:44 • 0 comments

  so before I make a PCB and order it for a lot of money (that's almost true, I have a coupon), I thought I buy parts for a lot of money, but hey - there's more money to collect now [http://hackaday.com/2017/04/18/up-up-up-2k-more-seed-funding-for-projects-that-matter/].

  Some almost breadboard friendly 74LVC8T245 were ordered, although they have their pinheaders upside down. [http://www.ebay.de/itm/302193394421]

  I have an ESP32 basic adapter board (dual row headers, no power converting), but I'll wait on the breadboard adapter I've ordered, with all the bells and whistles. (full disclosure, I wrote balls the first time)

  With that the 20bugs on that project are almost spend :) but it's good to have it. There are also two #Hornbill in the making, but they arrive much later.

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