M5Stack User Meeting Vol.6, Tokyo Japan, 2019/10/30

1. M5Stack drives
16x64 LED matrix
with HT16K33
M5Stack User Meeting Vol.6
Tokyo, 2019/10/30

2. 16x64 LED matrix

3. 1.
What is
HT16K33
?

4. RAM Mapping 16*8
Very few additional parts 120 at aitendo
HT16K33
Common
Source
Row
Driver
RAM
16x8bit
I2CM5Stack
RC
Oscillator
8
16
8x8 8x8
SOP28

5. HT16K33 x 8 on an I2C
Voltage Level Conversion
Configuration - 16x64 LED Matrix
M5Stack
0x70 0x71 0x72 0x73 0x74 0x75 0x76 0x77
Level-
Converter
5V
3.3V
I2C

6. 2.
What is
I2C
?

7. Inter-Integrated Circuit
SDA Serial DAta
SCL Serial CLock
Pull-upped to 3.3V
M5Stack inside
GPIO21
GPIO22
I-Squared-C, IIC, I2C
Addressable (7bits) 0x08 – 0x77
0x5A 0x290x57 0x48
Grove

8. I2C Address Map of M5Stack
Conflict
with
HT16K33

9. Look into Wire.h of Arduino-
ESP32
Wire1
is
Available

10. 3.
Level
Converter

11. Voltage of I2C
5V
Input
3.3V
Output
L
Voltage
H
L
H
1.5V
3.5V
5V
3.3V
0V
3.3V
5V3.3V

12. Level Converter for I2C
L
L
5V
3.3V
Built-in pull-ups
Body diode

13. Strapping Pins
GPIO12
GPIO15
GPIO0
GPIO2
GPIO5
Be careful of external pull-up / pull-down

14. 4.
Signage
in Japanese

15. UTF-8 to Japanese-Font
UTF-8
To
JIS
JIS
To
Font
Font index Font data
Font
Index
UTF-8 to JIS
Table
M5Stack
String
Font
To
I2C
LED
Shinonome(東雲)

16. 6.
Conclusion

17. Conclusion
Utilize M5Stack
• Wire1 is available in addition to Wire
• Be careful of the strapping pins
• The microSD is useful for Japanese fonts
Next Steps
• Some Web API or so, for text contents
• Movies and animations
• Full color or gray scale by modern devices

18. Copyright BotanicFields, Inc.
2019/10/30
M5Stack User Meeting #6
WingArc 1st Inc.
Roppingi, Japan
Thanks!