OKDO E1 Unboxing

[#1]

Unboxing video of the low cost OKDO E1 board.    As a quick demo, I hooked up the E1 to a low cost  240x240 Pixel IPS display from buydisplay.com.

[mark2]

Nice video, Eli. 

At 7 minutes you mentioned needing 3.3 volts for your display. You should be able to hook up 3.3 volts on the X101 connector, pin 1. The schematic labels this VDD_TARGET. It's derived from N400 Torex XC6206P331MR-G and should be good for 200mA. LPC55S69 will take in the region 10mA and debug interface LPC11U35 takes about 12 mA.

[Eli_H]

Good information Mark.     I realized this after I had gotten everything recorded.       My brain was really looking for a +3.3v net label and I completely missed VDD_TARGET.    +3.3v is definately availabe on the pin headers for user acces.

[chris9]

I have acquired the E1 board and downloaded the IDE.  I have successfully completed the led_blink example.  Now I am trying the hello world example and failing.  Where can I turn for help?  Everything built OK.  My console says it is a semihosting telnet console.  The debugger stopped at a breakpoint and I resumed execution.  The debugger window says the program is running.

I can't find the output.

I'm running on Ubuntu 18 something.  

I put a printf in the while(1) loop so it would steadily be doing something.

Now I see two commands in "top" that are using CPU:

redlinkserv
crt_emu_cm_redl

So it seems to be happily doing something.  It is just not showing up anywhere I can find it. 

[mark2]

Hi Chris,

I expect that the code has hung up in the clock initialisation routine.

The LED blink example probably sets up the clocking with function call BOARD_BootClockFROHF96M().

The hello_world example probably configures the clocks with BOARD_InitBootClocks() which then calls BOARD_BootClockPLL150M().

This PLL function call initialises the 16 MHz crystal, and uses it as a reference for the PLL0. Then waits for PLL0 to lock. Only problem is that there is no 16 MHz crystal fitted to OKdo E1 board. The led_blinky project runs the chip from the fast 96MHz internal free-running oscillator without needing the PLL.

You can refer to my blog post on the topic https://mcuoneclipse.com/2020/05/26/help-my-okdo-e1-board-hangs-up-solved/ and also watch my YouTube video series all about OKdo E1 board. Search for embeddedpro on YouTube.

Mark

Mark Dunnett

embeddedpro ®

+44 7734 848055

[chris9]

Hi Mark!  Thanks for  your help.

I found a happy ending.  Having already been successful with led_blinky.c and the OKdo tutorial, I decided to add a printf in the timing loop.  I also needed to include stdio.h at the top.  And that works just fine printing a line every second.

I noticed that the  hello_world examples (there are three) all seem to reference the UART in their descriptions  (and SWO?).  So maybe I was just picking the wrong example.

But I have terminal output now so I am a happy guy.

Thanks for your hard work on the videos and blog posts.