Renesas Envision Kit RPBRX65N Roadtest Part One - Introduction

27 Nov 2019

I applied to road test the RX65N MCU EV kit for two reasons:

I thought that I could test the product by re-producing the HMI (Human-Machine Interface) that I created for my last project - a bench power supply - which uses a 4Duino from 4D Systems. I understand that this is an evaluation board for the RX65N group of micro controllers so any conclusions must be made in light of that specific purpose, but it comes with an LCD and provision for the mounting of Arduino headers and SD card. By re-creating something I already have, I would be exercising the board and the micro controller against a known working solution (something I understand) as well as attempting something a little more complicated: the removal/replacement of the LCD in order to mount the headers and SD card. I half suspect that hobbyists, like myself, would look at the opportunity this board provides to use it as a front-end controller in a project; even if we call this a ‘prototype’ - and I think that is reasonable given that it is an evaluation board - my approach would test Its ease of use for such a purpose.

It isn’t my intention to do a direct comparison against the 4Duino as that is marketed as a production-ready solution so would be unfair. Inevitably, I will make some comparisons, particularly where the 4Duino has proved difficult to work with and how the evaluation board approaches the same issues.
I have very little experience of these types of modules (although extensive software engineering experience) so the road test will very much be from the perspective of how someone new to this gets up and running, productive and able to achieve positive results. This should bring a different perspective to the road test as it will highlight the support and help available for someone in a similar position. It will also bring out the complexity (or otherwise) of using this micro controller and developing a solution for similar projects, or even the efficacy of using the evaluation board itself.

The one thing I really want to re-iterate and make clear, in the interests of fairness to Renesas, is that this is an evaluation board for the micro controller and not a production solution. It would be unfair of the road test to review it in any other way.

Unboxing, information supplied and ease of access to additional information

I have a number of expectations that I’d like to see the package, as supplied, meet:

Well packaged so that the module is unlikely to be damaged in transport
A quick start guide to get it going so I can see that it is actually working
A link to check for firmware upgrades and instructions for doing so
A guide or links for next steps, tools and further information. I’d like the toolset to be natively available for MacOS but I don’t have high hopes here. I do have a Win 10 Pro VM running on my Mac so it won’t be an obstacle.

I’m not expecting realms of printed documentation, nor am I expecting hand-holding to use it, but I do want to see that I can get up-and-running without excessive trouble in digging out relevant information to do so.

The kit comes in a blister pack held within a much larger cardboard box so is well protected against the vagaries of delivery companies.

My particular example followed a route from Illinois to Kentucky to Pennsylvania to Stanstead to Stanford Le Hope to Northampton and finally my house so it certainly passed through a number of hands without mishap.

Introduction to the Board

I can see from the box that a quick start guide is provided and on opening, the ‘kit’ provides the evaluation board, a USB cable and the guide. The LCD has a protective film which is not unusual and given the number of marks and fingerprints on the display obviously needed. I’m really pleased that a USB cable is included as I’m never able to locate one when I need to, and doubly pleased that its just a standard USB A to Micro B and not some non-standard port.

The quick start guide really is just that - you can read it in the image above. Nevertheless, it is what I was looking for: information that will let me confirm the board is not DOA. It also provides the link to more information and the development tool.

There is another quick start guide available on line here. This contains data flow diagrams for updating the firmware which are a little confusing at first observation, but I’ll come back to it when I’m ready to update the firmware - the 2D drawing engine demo help text implies it needs a firmware update to show the operation of the graphic accelerator.

Additionally, there is an Envision Kit user manual here. Having read through this, it gives a good overview of the board, components, port mappings, interrupts and configuration.

Let’s take a look at the board itself (excuse the reflection.)

The most obvious elements are the flex-PCBs linking to the capacitive touch-enabled TFT-LCD, which is a WQVGA (480x272 pixels) physically measuring 105mm x 67mm (4 1/8” x 2 5/8”) with a visible area of 95mm x 54mm (3 3/4” x 2 1/8”) - 110mm (4.3”) on the diagonal. It is a 24-bit colour display but Renesas has it connected as 16-bit colour with mapping between the two for managing colour variation. It’s not clear if this is because the onboard graphic controller is only capable of 16-bit. The visible area is well positioned within the physical display and is not offset to leave unpleasing borders around the sides. This I think will turn out to be more useful than might be immediately apparent: the visible area is bordered by a uniform black area that will make it a lot more pleasing when mounted and in operation as a prototype. When the visible area is offset, a lot more shenanigans are required when mounting so that it doesn’t look misplaced or awkwardly positioned. As a comparison, see what the 4Duino provides with a thick border on one side plus a silver trace and visible connectors:

The MCU is bang in the middle; the components are clearly annotated and I expect these can be reviewed in the Schematic - a document only available to registered users, something I will do in the next instalment.

As this is an evaluation board, some components can be added by the customer. Although not populated, these are all traced to ports on the RX65NE:

Arduino Headers: CN10 map to Analog A0 to A5 pins; CN8 map to power and ground pins; CN13 and CN12 map to D0 to D13, aref, SCL/SDA and GND pins. The Envision board can be powered through the USB-microB connection (lower right hand side of the PCB) and it does seem possible to power the board from the 5V Vin pin by the application/removal of 0Ohm jumpers. However, the debugger must be powered from the USB socket however else the board is powered.
SD Port and power management
Joystick - there is currently one connected user switch, blue marked SW2, but this will allow the connection of a more complex input mechanism.
Ethernet port and transceiver

Renesas has given part numbers that can be used in these positions which is handy as it indicates they have been tested for use. I am particularly interested in the Arduino headers and SD card extensions as they will be part of the Road Test; I’m also a bit nervous about those flex PCBs which will need to come off to remove the LCD so those components can be soldered to the board. That’s for later and hopefully I will find information that helps in the process.

The headers at the top are spare MCU port headers with no specific definition - the User Guide doesn't explain these - but my assumption is that these are mapped to ports on the MCU so that they can be used for whatever purpose needed. The switches to the bottom right of the MCU are for configuring the onboard E2 debugger and configuring the USB/Serial UART Operation. I will certainly be using the onboard debugger and If time permits, I shall be investigating the latter. It is possible to use the board with an external E1 debugger by connecting to headers that are currently hidden under the LCD flex PCB.

Initial Thoughts

Given my expectations above, the package as delivered meets them fully and my initial impression is positive. From the Quick Start guide and the User Guide, it’s easy to get a high-level understanding of the board and how it might be used. Specifically, the User Guide is comprehensive without being overwhelming or beyond the technical understanding of anyone who would wish to use the board.

I’ve not shown the demos working as this is already available on Youtube here if you are interested. It’s a little cheesy but as well as the demo, it also covers some of the points I have described above. I can confirm the demos worked and do give a flavour of what can be achieved with the unit.

The next instalment of the review will cover getting to grips with the board:

Setting up a Renesas account
Updating the firmware
Installing tools (last possible moment however given the current 60-day time limit!)
Looking at the e-learning provided
Checking out the forum and its usage