Difference between revisions of "LB-68B50-01"

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[[file:LB-6850-01_FRONT_REV1(BLK).png]]
+
[[file:LB-6850-01_FRONT_REV2(BLK).png]]
  
 
== Features ==
 
== Features ==
Line 5: Line 5:
 
* Serial/Parallel I/O Card
 
* Serial/Parallel I/O Card
 
* 68B50 UART
 
* 68B50 UART
* Baud Rate Clock (38.4k baud oscillator)
+
* 1.8432 MHz oscillator
 +
** Baud Rate Clock (38.4k baud oscillator)
 
* XIAO RP2040 CPU
 
* XIAO RP2040 CPU
 
** USB/Serial
 
** USB/Serial
Line 14: Line 15:
 
== Design ==
 
== Design ==
  
=== ACIA ===
+
=== ACIA -Rev 2 ===
 +
 
 +
[[file:LB-68B50-01_ACIA-Rev2.PNG]]
 +
 
 +
* 68B50 UART
 +
* Baud Rate Clock (38.4k baud oscillator)
 +
 
 +
=== ACIA -Rev 1 ===
  
 
[[file:LB-68B50-01_ACIA.PNG]]
 
[[file:LB-68B50-01_ACIA.PNG]]
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* Baud Rate Clock (38.4k baud oscillator)
 
* Baud Rate Clock (38.4k baud oscillator)
  
=== XIAO RP2040 CPU ===
+
=== XIAO RP2040 CPU - Rev 2 ===
 +
 
 +
* Fix 3.3V levels
 +
 
 +
[[file:LB-68B50-01_ACIA-Rev2.PNG]]
 +
 
 +
* USB/Serial
 +
* Drive SPI I2C 8-bit parallel port expander
 +
* SD card
 +
 
 +
=== J4 - FTDI Header (Rev 2) ===
 +
 
 +
[[file:LB-68B50-01_J4_FTDI.PNG]]
 +
 
 +
* 5V levels
 +
* Pinout
 +
# GND
 +
# CTS (in)
 +
# VCC
 +
# TX (out)
 +
# RX (in)
 +
# RTS (out)
 +
 
 +
=== XIAO RP2040 CPU - Rev 1 ===
 +
 
 +
* Fatal flaw, can't use the RP2040 since the UART voltages are 5V and the RP2040 doesn't work at 5V
  
 
[[file:LB-68B50-01_RP2040.PNG]]
 
[[file:LB-68B50-01_RP2040.PNG]]
Line 29: Line 62:
 
* SD card
 
* SD card
  
=== Parallel Port ===
+
=== Parallel I/O Port ===
  
 
[[file:LB-68B50-01_MCP23008L.PNG]]
 
[[file:LB-68B50-01_MCP23008L.PNG]]
  
=== SD Card ===
+
* 3.3V levels
 +
* I2C Bus driven from RP2040
 +
* Int to RP2040
 +
 
 +
=== SD Card (Rev 2) ===
  
 
[[file:LB-68B50-01_SD_CARDL.PNG]]
 
[[file:LB-68B50-01_SD_CARDL.PNG]]
 +
 +
* Connected to RP2040
 +
* Can be used to send program code to the CPU
 +
 +
=== SD Card (Rev1) ===
 +
 +
[[file:LB-68B50-01_SD_CARD_Rev1.PNG]]
  
 
* Need to not install level translators
 
* Need to not install level translators
* Need to shot across the SD card lines
+
* Need to short across the SD card lines
  
 
=== Backplane ===
 
=== Backplane ===
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== Mechanicals ==
 
== Mechanicals ==
 +
 +
=== Rev 2 ===
 +
 +
[[file:LB-68B50-01_Rev2_MECHS.PNG]]
 +
 +
* Move J3 GND, VCC silkscreen over
 +
 +
=== Rev 1 ===
  
 
[[file:LB-68B50-01_MECHS.PNG]]
 
[[file:LB-68B50-01_MECHS.PNG]]
  
 
== Checkout ==
 
== Checkout ==
 +
 +
=== Rev 2 ===
 +
 +
[[file:LB-6850-01_FRONT_REV2(BLK).png]]
 +
 +
* Removed U2 voltage translator connections to SD Card and connect to serial lines between 5V ACIA and 3.3V RP2040
 +
* Lift pin U1-8
 +
* Lift pin U1-10
 +
* Connect U1-8 to U1-10 to Vcc
 +
* Add FTDI connector
 +
 +
=== Rev 1 ===
 +
 +
[[file:LB-6850-01_FRONT_REV1(BLK).png]]
 +
 +
* Do not install level translator U3
 +
* Short across the SD card lines
 +
** Jumper U2-13 to U2-2
 +
** Jumper U2-12 to U2-3
 +
** Jumper U2-11 to U2-4
 +
** Jumper U2-10 to U2-5
 +
* Cut etch U1-8
 +
* Cut etch U1-10
 +
* Add jumper U1-8 to U1-10 to U1-12
 +
* Cut etch U1-14 (E pin of ACIA)
 +
* Add jumper U1-14 to J1-49 (VDA)
  
 
== Assembly Sheet ==
 
== Assembly Sheet ==
 +
 +
* [https://land-boards.com/LB-68B50-01/LB-68B50-01_Rev1_ibom.html Interactive BOM]

Latest revision as of 23:03, 23 August 2024

LB-6850-01 FRONT REV2(BLK).png

Features

  • Serial/Parallel I/O Card
  • 68B50 UART
  • 1.8432 MHz oscillator
    • Baud Rate Clock (38.4k baud oscillator)
  • XIAO RP2040 CPU
    • USB/Serial
  • 8-bit parallel port expander
  • SD card
  • 100x50mm card

Design

ACIA -Rev 2

LB-68B50-01 ACIA-Rev2.PNG

  • 68B50 UART
  • Baud Rate Clock (38.4k baud oscillator)

ACIA -Rev 1

LB-68B50-01 ACIA.PNG

  • 68B50 UART
  • Baud Rate Clock (38.4k baud oscillator)

XIAO RP2040 CPU - Rev 2

  • Fix 3.3V levels

LB-68B50-01 ACIA-Rev2.PNG

  • USB/Serial
  • Drive SPI I2C 8-bit parallel port expander
  • SD card

J4 - FTDI Header (Rev 2)

LB-68B50-01 J4 FTDI.PNG

  • 5V levels
  • Pinout
  1. GND
  2. CTS (in)
  3. VCC
  4. TX (out)
  5. RX (in)
  6. RTS (out)

XIAO RP2040 CPU - Rev 1

  • Fatal flaw, can't use the RP2040 since the UART voltages are 5V and the RP2040 doesn't work at 5V

LB-68B50-01 RP2040.PNG

  • USB/Serial
  • Drive SPI I2C 8-bit parallel port expander
  • SD card

Parallel I/O Port

LB-68B50-01 MCP23008L.PNG

  • 3.3V levels
  • I2C Bus driven from RP2040
  • Int to RP2040

SD Card (Rev 2)

LB-68B50-01 SD CARDL.PNG

  • Connected to RP2040
  • Can be used to send program code to the CPU

SD Card (Rev1)

LB-68B50-01 SD CARD Rev1.PNG

  • Need to not install level translators
  • Need to short across the SD card lines

Backplane

LB-68B50-01 BKPL.PNG

Mechanicals

Rev 2

LB-68B50-01 Rev2 MECHS.PNG

  • Move J3 GND, VCC silkscreen over

Rev 1

LB-68B50-01 MECHS.PNG

Checkout

Rev 2

LB-6850-01 FRONT REV2(BLK).png

  • Removed U2 voltage translator connections to SD Card and connect to serial lines between 5V ACIA and 3.3V RP2040
  • Lift pin U1-8
  • Lift pin U1-10
  • Connect U1-8 to U1-10 to Vcc
  • Add FTDI connector

Rev 1

LB-6850-01 FRONT REV1(BLK).png

  • Do not install level translator U3
  • Short across the SD card lines
    • Jumper U2-13 to U2-2
    • Jumper U2-12 to U2-3
    • Jumper U2-11 to U2-4
    • Jumper U2-10 to U2-5
  • Cut etch U1-8
  • Cut etch U1-10
  • Add jumper U1-8 to U1-10 to U1-12
  • Cut etch U1-14 (E pin of ACIA)
  • Add jumper U1-14 to J1-49 (VDA)

Assembly Sheet