Actual Size (100dpi, click to zoom)

This is a generic RX-62N breakout board with the following features:

• Compact 2.8 by 3.3 inch format
• Footprints for both 144 and 100 pin devices
• Both E1 and gRX interfaces (for programming, debugging, etc)
• Device USB port pre-wired
• LEDs for Ports P7.4 and P7.5 (144-pin chip only)
• Two breakout pins for each MCU pin - inner header is for probing/debugging, outer header is for connecting to other boards.
• Powered by USB cables if the USB circuit is soldered on.
• USB circuit is optional - can be populated as E1-only to reduce cost.
• Mostly 8/8/20 rules, except for some 6 mil traces between the two MCU footprints. Two-sided board reduces cost.
• User-solderable with standard irons (fine-tip is better though :) - layout allows for either 0603 or 0805 parts.

• Schematics/Layout/Bom (pdf)
• Schematics (gschem)
• Layout (pcb)
• BOM (Digikey, 0603)
• BOM (Digikey, 0805)
• BOM (full, CSV)

Support for this project is via community volunteers at the Renesas Rulz web site. I'm not making a lot of money on these, so don't expect much personal service.

The design of this board was done using The gEDA Suite for both schematic capture and board layout.

The fab for this run was Sierra Proto Express via their No-Touch service.

Ordering/Shipping Notes

The ordering option here is for a BLANK PCB. Cost is US$ 6.25 per blank pcb ($100/16 appealed to my inner geek). If you order just one, I'm going to stick it in an envelope taped to your invoice. 2-10 ships in a padded envelope. More than that gets a flat rate box. International: I've been having trouble with international, so if you don't get it after two weeks, email me. All payments are via PayPal, but they do let you use a credit card.

Current stock: 38     Quantity: at $6.25 each

Assembly/Usage Options

The RX-62N Multi-Breakout Board can be built in many ways depending on which options you need, which programmers/emulators you'll be using, and how you want to power the board. You can also populate any RX-621 or RX-62N MCU chip in either the 100 or 144 pin TQFP packages. The RX-62T is not compatible.

Note that the LEDS P74 and P75 do not connect to any pin on the 100-pin package; if you install a 100-pin RX chip, there's no reason to install the LEDS, unless you want to jumper them to other pins via the headers.

Assembly Notes: The two diodes D1 and D2 do not have polarity marks on the initial run of boards. The mark is towards the USB connectors, as shown in the design files and PDF drawings. The mounting holes are sized for #4 screws.

Cables			Power	Parts Populated					OS	Notes
E1	gRX	USB		E1	JP	gRX	LDO	USB
Y	N	O	E1	Y	O	N	N	O		Power, programming, debug all from E1. Optional power from other source via headers.
Y	N	Y	USB	Y	O	N	Y	Y		Power from USB, programming, debug from E1
O	N	Y	USB	O	Y	N	Y	Y		Power from USB, programming over USB via FDT or rxusb; manual jumper/reset
N	Y	Y	USB	O	Y	Y	Y	Y		Power from USB, programming over USB via FDT or rxusb; manual jumper/reset, serial console via terminal emulator
N	Y	N	gRX	O	R	Y	Y	O		Must install at least the RESET_GRX header, set for GRX. Program via gRX protocol (serial), serial console.
N	Y	Y	gRX	O	R	Y	Y	Y		Must install at least the RESET_GRX header, set for GRX. Program via USB protocol under gRX control, serial console.

Notes:
JP = configuraton jumpers (MD0, MD1, RESET_GRX, BIG_LITTLE)
gRX = FT232R chip (U3) and related circuitry, see schematics
LDO = 3.3v low-dropout regulator (U4) and related circuitry
USB = RX device USB and related circuitry
O = optional, R = at least RESET_GRX installed

If you've never hand-soldered fine-pitch QFP parts before, here's how I do it:

• Using pen flux, flux the PCB and the bottom of the QFP leads.
• Using your iron carefully place a dab of solder on two pins in opposite corners (i.e. pins 1 and 72, for a 144-pin part).
• Place the QFP on the pcb where you want it. Verify the placement, and then heat up ONE pre-soldered pad so it solders that corner. Make sure the part is still in the right place; it's easy to heat that one pad and move it.
• Solder the other corner. Verify position again. Make sure both corners are soldered and the part won't move.
• Put a small blob of solder on the iron, and solder the two sides you haven't soldered yet. Too much solder is OK, and in fact easier. A big tip is fine for this.
• Use solder wick to remove excess solder.
• Repeat for the other two sides.

Soldering the 0603/0805 parts is similar - pre-solder one pad, hold part in place while reheating the solder, solder the other pad.

Note: After assembly, remove excess "no clean" flux from around the RTC circuit (xtal, caps, RX pins) and the USB pins (gRX, FT232R, USB, and RX pins). Some no-clean fluxes conduct slightly, which might corrupt these signals.

Header Options

• Male headers - breakaway - order two Sullins PEC36DAAN (Digikey). Break/cut both into two 36-pin rows. Break one of those further to produce the two 8-pin headers.
• Male headers - not breakaway - order two 67997-472HLF (Digikey) and cut them with a knife or scroll saw. They're cheaper, but they don't break by hand as easily.
• Female headers - order two Sullins PPTC182LFBN-RC (Digikey) and two Sullins PPTC042LFBN-RC (Digikey)

This is what the original prototype looks like assembled. Note that I chose to put female headers on the outer ring, and male headers on the inner ring. I use the male headers with my logic analyzer and the female headers with my solderless breadboards, but of course either row could be populated with any type of connector.

The inner ring has the port numbers next to each pin. In this example, you see Port PD.0 through PD.3, P9.0 through P9.3, P4.4 through P4.7, and Vdd (V+) and ground (V-). The port numbers are the same for the 144 and 100 pin devices, but the alternate functionality varies.