SD card boot for Banana PI R4 board does not boot

Banana Pi Router design BPI-R4/BPI-R4 Pro(MT7988)
1

Hi,

I have recently started looking into a Banana PI R4 board and am running into a boot issue. I have listed the steps I have undertaken below.

I looked into the documentation for Banana PI R4 board for SD card boot. I have performed the following and followed the documentation.

  1. keep the dip switches to (1,1) as suggested by documentation for SD boot
  2. use dd to write zeroes to the SD card and later flash the image on to the SD card. Tried with BalenaEtcher too.
  3. Since the WiFi card is attached, move the SW4 to ON position
  4. connected the USB-toTTL adapter with TX and RX crossed and GND to GND

Once the SD card is inserted and power is provided (12v - 5 A) through the barrel jack, the red lights come up which shows power is coming to the board. But nothing else seems to happen

  1. minicom shows no output (settings 115200/Flow control off/parity none)
  2. No blue light blink (as read in some of the posts) indicating boot is seen.

Can anyone kindly provide any inputs on how to proceed further? Since, minicom is not showing any output and the blue light never comes up, I can only think that the boot process never started. If so, any further actions to take in order to get to know what is happening?

A couple of additional steps also attempted which also did not work

  1. I attempted the boot by removing the WiFi card to see if power was an issue. Did not help.
  2. Tried booting with official image, as well as a self compiled image to see if something was wrong with the image. behaviour is same.

Any inputs will help me to start out on Banana PI R4 and is appreciated

Thanks and regards Vivek

2

I recall my R4 has factory shipped with a bootable image in the NAND. So you may give it a try without the WiFi module installed.

Also, worth trying without the debug console connected. See if the LEDs light up. Rea always. Then blue. Then Blue transits into Green (which means the kernel is running).

3

Is the uart adapter 3.3v? Else you can brick the soc. You can measure it with multimeter between tx-gnd when not generating traffic (data pulls tx to gnd).

4

Hi @kvic ,

Tried this. Ours does not seem to have a builtin image.

5

Hi Frank,

We checked the datasheet and find that the USB-TTL provides 3.3V logic level as stated below in the datasheet

The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets.

We are using DigiKey - 1528-2128-ND USB to TTL adapter

6

Which chip does it use? Older bpi boards had issues with profilic chips and so i focused on to cp21xx and ftdi

Do not connect powerpin of the adapter Have you ever seen uart output on this board and adapter? Just to make sure connection and settings are right

You use the dedicated 3pin socket?

7

Hi Frank,

Our usb-ttl is 2102 based. We are not connecting power via any external source to uart if that is what you you are asking.

Thank you Vivek

8

Hi Frank,

We attempted to bring up another Banana PI R4 and we were successfully able to bring it up with the same steps that fail for the other board. We have a snapshot of the working and the non working board attached.

We see the following in the non-working case:

  1. The LEDs near the UART pins - both are showing green
  2. The red pwr LED button is on and the green LED never comes up
  3. Two of the Ethernet (1 WAN and the other LAN) have green LEDs that are always ON without any ethernet cable connection.

Non-working-board
Non-working-board900×1600 144 KB

For the working case:

  1. The LEDs near the UART pins. - only one is showing green
  2. The red pwr LED turns on and after a few seconds, the green LED next to it turns on
  3. The ethernet LEDs are not at green always.

Working-board
Working-board900×1600 133 KB

can you kindly suggest anything that you might be able to glean from this behaviour and let us know

Thanks and regards Vivek

9

The red PWR LEDs are hardwired, so they’re always on. The two LEDs near the USB ports are for the SFP cage. The green LED (next to the PWR LED) will be turned on by the bootloader.

Can you describe the boot mode switches again? According to your first photo, it looks like facing upwards, but the 1-1 position is to face downwards. Up-up (0-0) is an undefined state in this board.

Edit: The green LEDs on the ETH ports are strapping pins when the device is powering on (two of them are related to the boot mode switches, and the other two are for the memory density if I remember correctly). So there are completely normal to signal something before the system is running. After the system boots up, the switch will take over to controlling them.