Renesas Electronics Corporation is a Japanese specialist of semiconductors including microprocessors and microcontrollers, along with a large rang of boards and kits that make it easy to try out specific features of chipsets. They have their roots in their humble beginnings in 2002 when they were known as Renesas Technology, later changing to Renesas Electronics in 2010 results from a merger with NEC Electronics.
You can Renesas' site at:
My first involvement with Renesas products was with the R8C Tom Thumb, which you can read about on this page:
But more recently, in 2025, I got from eBay a job lot of electronics which appears to be from Elstat Limited, a UK company liquidated in 2024, that specialised in coolers from what I found online. In the job lot were a number of Renesas development boards and accessories that it seems were very likely used by Elstat to prototype some of their products. The items are as follows; EK-RA2E1, EK-RA2L1, FPB-RA2E1, Capacitive touch application board, and RA2L1 Cap Touch CPU board. You can read more about them on this page along with any more Renesas boards I may get in the future.
Please note that the images featured on this page are downloadable from the bottom of this page for better viewing.
You can email me at james.boshikoopa@gmail.com
The EK-RA2E1 evaluation kit was designed to explore the features of the RA2E1 MCU (Microcontroller) Group (which is based on the Arm Cortex-M23), which you can learn more about at:
https://www.renesas.com/en/products/ra2e1
For the EK-RA2E1 board product page please go to:
https://www.renesas.com/en/design-resources/boards-kits/ek-ra2e1
At the time of writing this article in 2025 the board is 'active' and selling for $56.49 (£41.39). The page has links for the Quick Start Guide, manual, schematic, and software. The manual is from 2021 and since I got the board from a job lot with PCBs from around 2022 the board is possibly from 2021.
To help users get started quickly the EK-RA2E1 board comes pre-programmed with a Quick Start Example project (the source code is provided in the EK-RA2E1 example project bundle found on the previously linked to page).
The following video gives an overview of the RA2E1 board and the Quick Start Example project:
Now looking at the EK-RA2E1 kit in detail I will describe the parts of interest but note that your kit may differ slightly.
On the top of the box it says:
EVALUATION KIT
EK-RA2E1
Version 1
Evaluation Kit for RA2E1 MCU Group
Renesas RA Family of 32-bit MCUs with Arm Core
Part Number:
RTK7EKA2E1S00001BE
The label shows it was bought from Farnell on 01/07/22.
The box underside lists the board features including the Quick Start Example project, along with the URL renesas.com/ra/ek-ra2e1. It also mentions the box contents (EK-RA2E1 board and micro USB cable).
Next, lets look at components of interest on the EK-RA2E1 board:
PCB top side
Top half:
GND x2, 3.3V, +5V IN ‘hook’ connections
J25 and J26 2x6 Female PMOD connectors x2
J20 2x10 Male DEBUG3 connector
J13 2x5 Male DEBUG2 connector
J10 Female micro USB DEBUG1 connector
Various headers with jumpers
J21 and J22 Mikro BUS (two Female 2x8 connectors)
J27 and J28 Two Seeed grove connectors 4-way Male JST
J30 QWIIC SparkFun 4-way Male miniature JST
J14 unpopulated connector labelled as 'J-LINK S124 RE-PROG' on schematic
J18, J19, J23, J24 Arduino Female headers (8-way, 6-way, 10-way, 8-way)
User buttons S1 and S2, and RESET button
User LEDs LED1 - LED3 (blue, green, red), power LED4 (white), and debug LED5 (orange).
DZJA XHSS IC U8 ISL80102IRAJZ according to schematic, adjustable linear voltage regulator
R7FS124773 IC U7 Arm Cortex-M0+ Core 128KB flash 16KB SRAM. Datasheet:
https://www.alldatasheet.com/datasheet-pdf/pdf/948672/RENESAS/R7FS124773A01CNF.html
Various test points
On the PCB it has written:
EK RA2E1
Version 1
P/N RTK7EKA2E1S00001BE
renesas.com/ra/ek-ra2e1
Bottom half:
TP1 and TP3 MCU CURRENT hook points
J1 and J3 2x7 Male header RA MCU interface signals
J2 2x20 Male header RA MCU interface signals
Y1 20.000MHz crystal
Y2 32.768KHz crystal
R7FA2E1A92DFM IC U1 Arm Cortex-M23 core 16KB SRAM 128KB flash. Datasheet:
https://www.renesas.com/en/document/dst/ra2e1-group-datasheet
On the PCB it has written:
RA2E1 MCU
P/N R7FA2E1A92DFM
48MHz, 128KB Code Flash, 16KB SRAM, LQFP64
PCB bottom side
Various connector pinouts
Various pads can be broken for options
On the PCB it has written:
RENESAS
EK-RA2E1
Version 1
As written on the PCB underside the board is split into the larger top half 'System Control & Ecosystem Access' and the smaller bottom half 'MCU Native Pin Access'.
Please note that only a few R7FA2E1A92DFM pins are 5V tolerant when the chip is run off 3.3V as is the case for the development board - please see the datasheet for details.
You can power the EK-RA2E1 board through the USB debug port (J10) using a micro USB cable connected to a 5V power source. The white power LED (LED4) will light up and the Quick Start example project will begin to execute blinking the blue user LED (LED1).
I will now go over a few details from the Quick Start Guide:
Page 7: the board originally came with a type-A male to micro-B male cable.
Page 8: you can change both the frequency and intensity of LED1 when the Quick Start Example Project is running by using the user buttons S1 and S2. The supported frequencies are 1Hz, 5Hz, and 10Hz, and the supported intensities are 10%, 50%, and 90%, the default is 1Hz and 10% intensity. Additionally, when the board is connected to a PC via the debug USB connector Quick Start Example Project the kit information, MCU die temperature and user LED blinking frequency are displayed on a virtual terminal console.
Page 9: explains how to connect the board to a PC and run the example program. You need:
SEGGER J-Link USB Serial Drivers.
SEGGER J-Link Real-Time Transfer (RTT) Viewer, virtual terminal emulation application. It is included in the J-Link Software and Documentation Pack which can be download from segger.com.
So I went to:
https://www.segger.com/downloads/jlink/
And downloaded the Windows 64-bit Installer V8.70 2025-09-17, the most recent at the time and I installed using the default options.
I plugged the board into my Windows 11 laptop using a micro USB cable plugged into the DEBUG1 port and the board's LED1, LED4, LED5 were lit. Then the computer ‘ran into a problem’ (the now black BSOD) and it restarted. Looking in the Event Viewer I found:
The computer has rebooted from a bugcheck
After the computer rebooted I got ChatGPT to analyse the crash dump but it was only able to give hints as to properly identify the fault I would need to use WinDbg, however, it did suggest temporarily disabling ProtonVPN. So I closed ProtonVPN and plugged the board in and the computer didn't crash. Looking at the Event Viewer again, at the time I plugged the board in without it crashing, I saw ‘A service was installed in the system.’ and ‘Service Name: J-Link driver’. That driver is used by the board so perhaps there was a fault when it tried to load it only to crash the PC.
On the board LEDs LED1, LED4, and LED5 were on. Note that the power LED LED4 forms the ‘-’ between the ‘EK’ and ‘RA2E1’, which is a nice touch. LED5 was blinking very quickly, which supposedly shows the debug link is active.
In Device Manager the only thing I saw was ‘J-Link driver’ under ‘Universal Serial Bus Controllers’.
According to the Quick Start Guide the Quick Start Example Project preloaded on the board lights LED1 and LED2 (LED1 blinking, LED2 steady) but since the board is second hand likely it has other code running. Indeed, pressing S1 and S2 had no apparent affect on LED1 as would have been case for the preloaded example code.
I did open the J-Link RTT Viewer as mentioned in the Quick Start Guide since the board provides a virtual COM port, just to see if there was anything interesting generated by whatever code was running on the board. After entering the settings into J-Link RTT Viewer as shown in the Quick Start Guide I did the firmware update, which took about 6 seconds. LED5 was now rapidly flashing.
It was worth checking as the terminal view showed data that looked like it was related to elstat products, since I got the board amongst other items from an elstat clear-out. The text starts with a header declaring ‘Renesas FSP Example Project for r_sci_uart Module‘, ‘Example Project Version 1.0, and ‘Flex Software Pack Version 3.8.0’ so it looks like they adapted an example project. Another significant text is ‘The Pr2x V3 Project’, Pr2x-V2c was written on one of the elstat PCBs I got in the job lot so it looks like the EK-RA2E1 was used to prototype perhaps a later version of the elstat PCB.
The next interesting text: ‘DOOR_EVENT registered’ and ‘thermostat_on_door_event 0', then ‘**door_check** 0’ frequently repeated. The elstat control panels and PCBs I got in the clear-out have a door sensor so it makes sense.
At this point I knew the board works, I will look into whether the program code can be extracted for research purposes.
All content of this and related pages is copyright (c) James S. 2025