[Tutorial] How to use MRP11 with external oscillator
Step by step guide to using MRP11 Multi AVR Adapter with external oscillator.
Step by step guide to using MRP11 Multi AVR Adapter with external oscillator.
Following illustrates the steps of using MRP11 with external oscillator:
Identify the pin number for XTAL1 and XTAL2 on target MCU from datasheet. For example, ATmega328P has XTAL1 at Pin9 and XTAL2 at Pin10.
![]() |
Identify corresponding pins on MRP11 Zif Socket according to XTAL1 and XTAL2 pin of target MCU, For example, Pin9 and Pin10 of ATmega328P are located on MRP11 Pin12 and Pin13, respectively.
![]() |
Cut out two pieces of rectangle paper(size: 1cm x 0.5cm) and fold them in middle, as follows:
![]() |
Put these papers into identified XTAL1 and XTAL2 pin location on MRP11 Zif Socket. For example, put the papers on pin12 and pin13 of MRP11 as follows:
![]() |
Place the target MCU onto MRP11 and change the switch position following MRP11 user manual. Make sure the XTAL1 pin and XTAL2 pin of target MCU are inserted into the middle of papers, so that these pins can be isolated from MRP11. For example, the following illustrates ATmega328P is placed onto MRP11 and the switch is changed to “28-Pin”:
![]() |
Connect three wires to XTAL1 pin, XTAL2 pin and Pin20 (Ground) at MRP11. Please ensure wires at XTAL1 and XTAL2 pin are placed into the middle of papers and connected to target MCU pins, as follows:
![]() |
Followings explain three cases to connect MRP11 with external oscillator:
[Case A] Connect to on-board crystal oscillator via chip socket
To utilize on-board crystal, MCU at board is needed to be removed and wires from MRP11 are connected to crystal pins via chip socket. Following shows how to connect MRP11 with crystal on Arduino UNO board. Pin9 and Pin10 of Arduino UNO chip socket are connected to crystal, so these pins are used to connect to MRP11. The match connections are same as follows:
a. XTAL1 from MRP11 -> Pin9 at Arduino UNO
b. XTAL2) from MRP11 -> Pin10 at Arduino UNO
c. GND from MRP11 -> Pin8 at Arduino UNO
![]() |
[Case B] Connect to crystal oscillator on breadboart
To use crystal on breadboard, user need to connect the crystal, capacitor and wires from MRP11 as follows:
![]() |
[Case C] Connect to ceramic resonator
To connect MRP11 to resonator, user can connect the Pin12(XTAL1) and Pin13(XTAL2) from MRP11 to left and right pin on ceramic resonator and connect the Pin20(GND) to middle pin of ceramic resonator, as follows:
![]() |