ESPlay Micro

@Makerfabs sent me 2 PCBA Sample last week, so i could work for the firmware this weekend. After upload the fw i just surprise the sound and button didn't works, i spent two hours to see what happened. I didn't make any changes on button, then after reads the datasheet there's different i2c address scheme between PCF8574AT and PCF8574T. Earlier prototype PCF8574AT was used ( salvaged from 1602 lcd i2c backpack ) and the address 0x38 was used, with this sample PCF8574T the address is 0x20, one problem solved.

The Sound is different case, after 3 hours struggled with the programming the problem is not the software but really bad typos on schematics, the resistor for R-C filter was wrongly typed from 1 Ohm to 1 KOhm, swap the resistor with the right one and VOILA the sound works. The Sound output are really clean on the headphone and very low noise output from the speaker, really satisfied with the result. 

The Rev2.0 sample PCBA completed

So... Yesterday I finished a revision design for next PCB. I will double check it before sending it to manufacturer. This time the prototype PCB will be produce by @Makerfabs.

Here the changes in this revision so far, i called this pcb-rev2.0 :

• Audio amplifier chip would be replaced by PAM8403 and used only left channel since audio onboard speaker only mono. I used this chip because the that have inbuilt shutdown circuit and low noise audio profile.
• Change layout audio blocks, so audio system will be in one block to reduce noise.
• TP4056 li-ion charger replaced by LTC4054 since it smaller and less external components.
• Add usb plug detect and charger status, it will be monitored by esp32 to charge management.
• Add some ESD Protection on sdcard.
• Moved all port to the bottom edge pcb so it won't interfere while play.

Hi, a bit software updates!

Long ago i used a quick and dirty hack of GoGo launcher made by odroid-go community member. Now i built from scratch an Launcher Software for Esplay Micro using UGUI library and add some capabilities like uploading file to device using web browser. checkout my github page for code.

While built this launcher i found a little bit flaw on hardware side, seems the LDO not enough current to supply whole board while wifi enable, backlight TFT are glitching and sometimes esp32 reboot cause of brownout detected, decreasing WiFi TX power seems solve for now, default TX power is 20 dBm and decreasing half of it to 10 dBm uses less power.

Here some spoiler about it

Hi, a bit updated for software side. Actually this is a hardware project but have a good and optimize software is a must.
This week i've developed a launcher and emulator based on Odroid-Go and Pocketsprites. I adopt in-game menu like in Pocketsprite. Also I write a drivers for hardware, not optimized yet but all work. One missing is sound, it's not tested yet cause i don't have i2s chip for now.

A bit updated from software side, esplay now could play some games that runs on odroid go. I try ported duke nukem 3d from odroid go to be used on esplay micro. Also i still working for emulator, so far nes, gameboy, and sms are working well. Here is the proofing picture

I already receive a bunch of ESPLAY MICRO PCB from JLCPCB two months ago but could play with it just a week ago. I don't have any esp wrover lying around so i salvage from another project and decided to assembly the PCB. So far after a couple hours of soldering some smd components it lives with some design bugs found later. The board work as i expected but later i found out some button didn't work, after check the esp32 datasheet i forgot add pull up resistor for some GPIO Pin.

GPIO number 34, 35, 36, and 39 doesn't have internal pull up/down. No problem i just add some external ones then it work perfecty, add some note to add them on next board revision. here some picture of it.

ESPLAY MICRO running retro-esp32 launcher by @Eugene Andruszczenko on his Gaboze Express, an awesome launcher design.

added some pull up resistor to get some button working. Next i will design a 3d printed case for this. I have design for top case like this