i300 Pumpkin Board

The i300 pumpkin board comes in two variants:

The i300 pumpkin board is using the i300 (MT8362) platform.

Purchasing

The i300 pumpkin boards are available on Seeed:

Building

You can build an image for the i300 pumpkin board by setting the MACHINE variable in your local.conf to i300a-pumpkin or i300b-pumpkin.

MACHINE=i300a-pumpkin
MACHINE=i300b-pumpkin

For full build instructions, please refer to the top level README.md.

Display

The i300A Pumpkin support HDMI and the 7-inch Raspberry Pi touch display.

HDMI is working by default if you set MACHINE=i300a-pumpkin. If you wish to use the 7-inch Raspberry Pi touch display, the related overlay is recipes-kernel/dtbo/mt8167-pumpkin/panel-raspberrypi.dts

Warning

Using panel-raspberrypi.dtbo requires you to plug the 7-inch Raspberry Pi touch display to the i300A pumpkin board. Failing to connect it will prevent HDMI from working. If you only want HDMI, you should not use this overlay.

The i300A Pumpkin also supports the AVD-TT70WS-CN-134-A touch display. If you wish to use it, the related overlay is recipes-kernel/dtbo/mt8167-pumpkin/panel-avd-tt70ws-cn-134-a.dts

Cameras

The i300A Pumpkin board supports the following csi camera sensor:

  • Omnivision ov5645

If you wish to use the ov5645 camera, the related overlay is recipes-kernel/dtbo/mt8167-pumpkin/camera-ov5645.dts

Audio

Default Playback

By default, the pumpkin board ouputs audio on the jack connector.

It is possible to output the audio on the MT6392 PMIC mono lineout as well. To enable this output, you will need to change one of the alsa settings using the following command:

amixer set -c mtsndcard 'Codec_Loopback_Select',0 CODEC_LOOPBACK_DMIC_TO_SPK

Setting any loopback to the speaker will work.

In order to disable this audio output, simply disable the loopback by using the following command:

amixer set -c mtsndcard 'Codec_Loopback_Select',0 CODEC_LOOPBACK_NONE

Default Capture

By default, the pumpkin board captures audio using 2 PDM microphones that must be plugged directly on the board.

The following command is an example that will start a stereo record with a sampling rate of 48kHz and a signed 32bits bit format:

arecord -c 2 -r 48000 -f s32_le recorded_file.wav

It is possible to record using the jack microphone instead. In order to switch to this input, you will need to change a couple of alsa settings using the following commands:

amixer set -c mtsndcard 'AIF TX Mux',0 'Analog MIC'
amixer set -c mtsndcard 'Left PGA Mux',0 'CH1'

In this case, in order to record, the jack device will have to be specified as follows:

arecord -D hwjackmic -c 2 -r 48000 -f s32_le recorded_file.wav

Using the audio I2S inputs/outputs on the 40 pins header

At build time, it is possible to move from jack/pdm mics to the audio inputs/outputs available on the 40 pins header. In order to do so, you can set the I300_PUMPKIN_AUDIO_CONF variable in your local.conf to i2s.

I300_PUMPKIN_AUDIO_CONF=i2s

With this configuration, it is currently possible to use a 2channels I2S in device (named I2S2) for the capture and and 8 channels I2S out device (named I2S) for the playback.

Warning

Please note that the SD card will be disabled in this case as the SD card share its pins with the I2S 8 channels out device.

Here is the pin configuration to use on the 40 pins header:

Header pin

GPIO

Function

19

GPIO51

I2S2_MCK

40

GPIO55

I2S2_BCK

7

GPIO2

I2S2_LRCK

23

GPIO49

I2S2_DI

11

GPIO25

I2S_8CH_MCK

13

GPIO73

I2S_8CH_BCK

37

GPIO72

I2S_8CH_LRCK

22

GPIO71

I2S_8CH_DO1

18

GPIO70

I2S_8CH_DO2

15

GPIO69

I2S_8CH_DO3

16

GPIO68

I2S_8CH_DO4

I2S devices can be connected to these pins and, provided they don’t need any configuration and as a consequence don’t need any codec, they will work without any additional modifications. Regarding the I2S 8 channels out device, we can imagine using 4 x 2 channels I2S devices. In that case, the devices will share the same MCK, LRCK and BCK but will have a different data line each (DO1, DO2, DO3 or DO4).

MT7668 wireless chipset

The i300 Pumpkin board is integrating a MT7668 wireless chipset. By default the chipset comes with no MAC or BD address. Please refer to the MT7668 wireless chipset documentation to see how to program a MAC or BD address.

Device-Tree Blob Overlays (DTBO)

The following Device-Tree Overlays are supported:

  • panel-raspberrypi.dtbo: Raspberry Pi touch display (see Display section)

  • panel-avd-tt70ws-cn-134-a.dtbo: AVD-TT70WS-CN-134-A touch display module (see Display section)

  • camera-ov5645.dtbo: Ov5645 camera (see Cameras section)

Limitations

The software image has the current limitations:

  • OpenGL is not yet supported. Only OpenGL ES, OpenCL and Vulkan are supported.

  • X11 is not available (because of the lack of OpenGL)

  • NAND Storage is not yet supported