MCU-Link pro powering a LPC54S018-EVK

[mh_n]

Hello,

I have been using a LPC54S018-EVK board with a Dual CAN-FD Shield (OM13099). I have used my written software as well as provided SDK example "mcan_interrupt_transfer" to send and receive data through the CAN shield while using the debug probe that comes with the LPC54S018-EVK board; However, I was trying to use a MCU-Link pro instead and I ran into an issue. While powering the LPC54S018 board from MCU-Link pro, the CAN shield seems to not get enough power to function properly.

What I have done:

• Set JP6 on MCU-Link pro (to power target board)
• connect the 10-way SWD ribbon cable from J7 on MCU-Link pro to SWD on LPC54S018
• Connect VCOM IN  of MCU-Link pro to Tx on LPC54S018
• Connect VCOM OUT of MCU-Link pro to Rx on LPC54S018

What works:

• I can debug code
• I can flash software to the LPC54S018-EVK board
• I have access to COM port input and output

What does not work:

• CAN shield does not send/received data (also the LED on the CAN shield seems not as bright as usual)

I found out that powering the board separately using another USB cable connected to the "Power only" USB, solves the issue; However, I would like to power the board with MCU-Link pro if possible. I was wondering how I can do that.

Thank you,

Mohammad

[xiangjun_rong · Accepted solution]

Hi, Mohammad,

You want to connect only the MCU-LINK Pro with USB, and power all LPC54S018-EVK and Dual CAN-FD Shield from MCU-LINK Pro, it is NOT possible from design.

From the following circuit, the Pin1 of P1 connector can get 3.3V power from the MCU-LINK Pro, but it can not power the VDD_TARGET node even if you close the pin2&3 of JP2. In other words, the LPC54S018-EVK can not get power from MCU-LINK Pro.

I suggest you power the LPC54S018-EVK and Dual CAN-FD Shield with the J1 power only USB connector, and connect the MCU-LINK Pro with another USB connector as you have done.

Hope it can help you

BR

XiangJun Rong