SR-JV Wi-Fi Expansion Board

Table of Contents

Disclaimer

  • Experimental product. May not work for you. May not work at all.
  • Special care required when using multiple. See Wi-Fi Power Off
  • Shipping may be slow. Price may go up or down without prior notifications
  • P65
  • I have no control over how page-ID is generated in WordPress

About This Project

This board is a re-writable ROM card with a Wi-Fi based user interface. It can store a ROM image up to 8MB/64Mbit, usually custom authored, and be used in compatible Roland synthesizers in place of an original SR-JV80 series expansion card to research the sound generation and synthesizing.

Compatible Hosts

This card is designed to be compatible with all Roland synthesizer which have slot for SR-JV80 series expansion cards. However, not all hosts are tested.

SynthesizerSR-JV80 SlotsTested and Working?
JV-801
JV-901
JV-10001
JV-8801
JV-10101YES
JD-9901
FA-761
XP-302
XV-882
XP-504
XP-60/804YES
Up to 4 units with Wi-Fi off
JV-10804
XV-30804
XV-50804
JV-20808YES

Parts and Function

  1. Button – for activating Wi-Fi and resetting configuration
  2. Remote Button Header – user can solder a remotely mounted normally open button to this footprint. A button wired here has exactly same function as the onboard button
  3. Power Indicator – on when power is supplied to the board
  4. Status Indicator – blink slowly when Wi-Fi is on and no operation; on solid when operation in progress; blink rapidly when error; off when Wi-Fi is off
  5. USB connector – for powering the board when out of a synthesizer
  6. Expansion connector – for connecting to host synthesizer, the connector has been filed on some location to reduce stress
  7. Production header – for developer only, provides access to ESP32 UART, BOOT0 and RST. Can be used to program ESP32 in case the firmware is corrupted, or to develop own firmware

Board Info

Designed by me, Connor Zheng, in Beijing, China. Assembled in Beijing, China with components sourced globally. PCB by JLCPCB. 4-layer FR4, Lead-less HASL, RoHS 1, UL 94V-0. SAC solder.

Comparison with Sector101’s Romulator

This is not a clone of Sector101’s product. The Romulator is a more faithful reproduction of the original Roland cards, using nothing but 4x 2MB Flash on the card. The programmer is standalone and not included on the card. This means electrically the Romulator card is exactly same as original card, which won’t have power consumption issues, wireless interference or anything like that, and is guaranteed to work in all hosts. You will have to take out a Romulator card from the synth to re-program it.

This product use 1x 8MB Flash and incorporates a ESP32 wireless microcontroller as on-board programmer. It is easier to use, can be programmed while inside synth, however have higher power consumption. Due to the address encoding, compatibility is not guaranteed on all hosts (need testing, see compatibility matrix).

User Guide

Installation

Please follow the original Roland SR-JV80 series expansion card operator’s manual to install. Before installing make sure to unplug the mains power from the synthesizer. If you want to program/configure the card before installing, you can power the card by using a regular USB type-C cable and connect the other end to either a power supply or a computer.

Note: It’s highly recommended to use anti-static wrist-band connected to a solid ground connection to avoid static discharge damage to either the card or your synthesizer.

Note: If the board holder is too tight to rotate into place, do not force it. Leave it as is.

Note: If using multiple expansion cards it’s strongly recommended to configure Wi-Fi off in the configuration page.

Connecting to the Card

When the card is powered up and not in Wi-Fi off state, you can connect to the card’s Wi-Fi hotspot. Default name is “SR-JV-XXXXXX” where XXXXXX is the last 3 octets of the Wi-Fi interface’s MAC address and no password:

Once connected, open a new browser tab and navigate to “http://192.168.4.1“:

Click on any one of the link to go to their corresponding section.

ROM Content Management

Note: Change the synthesizer’s current selected patch/perform/rhythm to not include anything from the card before manipulating flash ROM. Otherwise the synth may crash and/or the synth patch data may get corrupted.

The status indicate whether the flash ROM is erased or programmed. Possible states are: ERASED, ERASING, PROGRAMMED, PROGRAMMING and UNKNOWN.

Before programming, the flash need to first be erased. Click “Erase Flash” to erase flash, this will take about 1 minute:

After the erase is finished, the page will automatically refresh.

Then you can program the flash with a image file. Browse for a BIN file and hit upload to write the flash, a full 8MB image will take 6 minutes to write:

Do not close the browser tab or disconnect Wi-Fi when writing. After writing is finished you need to power cycle your synthesizer to use the new ROM.

If the erasing or programming operation has been interrupted or failed before finish, a power cycle will recover the status to UNKNOWN and you can try program the same file again without erasing. In the state UNKNOWN you can either erase or write the flash. But if the flash is partially programmed and you try to program another file, the content will become corrupted and need to be erased.

Configuration

Wi-Fi Credentials Configuration

You can change the Wi-Fi hotspot name (SSID) and optionally set a password.

Note: SSID cannot include space (” “) and cannot be longer than 32 characters; Password cannot be shorter than 8 characters or longer than 32 characters.

Once you have decided on the SSID name or password, click submit to confirm it. A restart is needed for configuration to take effect.

Note: If you experience difficulty connecting with password changed, after you hit “submit”, instead of using the restart button, try do a power cycle. Depending on the operating system and wireless network card used, you may also have to “forget network” before connecting to it again, especially if the SSID name is not changed.

Wi-Fi Power Off Configuration

Installing more than one card without using one of the low power modes may cause your synthesizer’s 5V power supply to overheat, go into overcurrent protection, and/or be damaged. If you don’t need to change the content or if you have access to the button switch, just use Wireless Off mode.

Normally this card would consume about 150mA with Wi-Fi on, and when actively writing the current will be 200mA or more. When multiple cards are installed this will likely cause the synthesizer’s power supply to go into overcurrent protection. In such case, you can configure Wi-Fi off to minimize current consumption. If you experience RF interference, you can also use this function to eliminate it.

There are 3 options: Always on, Wi-Fi off with BLE wakeup, Wireless all off.

  • Always on: Highest power consumption. The Wi-Fi interface is always on, suitable when no interference and only 1 card is installed
  • Wi-Fi off with BLE wakeup: Medium power consumption. Wi-Fi will be off upon boot. Wi-Fi can be activated by button or Bluetooth. This is suitable for a closed chassis situation without a remote mounted button. Current consumption is about 80 mA when Bluetooth is advertising with an average of 30 mA.
  • Wireless all off: Lowest power consumption. Wi-Fi and BLE are off. Wi-Fi can be activated by button only. RF systems are shut down.

Once you have selected an option, click submit to confirm it. A restart is needed for configuration to take effect.

Also, after manipulating the flash ROM on one card, remember to return to low power mode by using the link in the webpage or power cycle, before moving on to wake next card.

Waking Up the Card/Activate Wi-Fi

In both Wi-Fi off modes, you can press the button to activate Wi-Fi, either the onboard one or a user-soldered remote mounted button switch. Press the button for about half a second until the status LED starts to blink slowly. When waking up from sleep, holding the button down won’t clear the config.

If using BLE wakeup, you can use a phone or computer to initiate a pairing attempt with the card. Navigate to the Bluetooth settings of your phone, and select the option for pairing a new device. The device name is same as the Wi-Fi SSID configured. Click on the device name to initiate a pairing. You may need to click more than once for it to work. The pairing attempt will fail, and Wi-Fi will be activated.

Note: It’s by design that the Bluetooth pairing attempt will fail. This eliminates the need for an app, and you won’t need to un-pair the device before next Bluetooth wakeup.

OTA Firmware Upgrade

If you are updating using a pre-compiled BIN file, skip this step. If you are compiling from source, select “Export Compiled Binaries” in Arduino IDE:

Select sketch BIN file and update:

After the progress reach 100%, the card will reboot to the new firmware and the page will redirect to homepage after 5 seconds. If Wi-Fi power off is configured, the redirect will fail. You need to wake the card again. Please disconnect Wi-Fi and reconnect to the card in such case. If you cannot connect to Wi-Fi after an OTA update, a power cycle will restore things to normal.

Note: If the BIN file is corrupted or wrong, and the ESP32 cannot boot, it will revert back to the working firmware. In rare case that the board cannot boot, it can be flashed normally by using the production headers and USB to TTL adapter. The ESP32 has an internal bootrom so it is not possible to actually brick it. Follow guides on developing ESP32 to know more.

Resetting Config

If you forget the password or otherwise need to reset the configuration, please follow these procedure:

  1. Power off the synthesizer or unplug USB power, wait at least 10 seconds
  2. Press and hold the button down
  3. While holding the button down, turn on the synthesizer or plug in USB, the STATUS LED will blink rapidly
  4. Continue to hold button down, after about 3 seconds STATUS will light up solid
  5. Release button, card will automatically reboot, config is cleared

If you let go of the button too early, the card will return to normal working mode and configurations will not be cleared. Resetting the configuration will not erase the flash ROM, but the ROM status will become UNKNOWN.

Open-source Hardware

Pending open source – this section will be updated later. It’s a work in progress and a mess I need to clean up before I can publish

Update on 15 Feb. 2025: Due to the bicycle accident I’m not in a position to deal with this. Postponed.

Buy Now

First batch has sold out. Thank you for your support. I already started to make second batch of 60 units. Stay tuned for updates. If you would like to subscribe to an email service for availability update, go to this page:

Stock availability notification subscribe – SRJV

Due to the bicycle accident, first batch buyers can expect outbound shipment before end of February.

Since this is first production run there may be bugs, unfixable hardware ones are also possible to exist. Compatibility is also not tested on all host synthesizers. I’d also greatly appreciate it if you can email me ( [email protected] ) with your result using this device, so that I can extent the compatibility matrix and improve upon.

Phone number is recommended for all destinations and REQUIRED for destination: Canada, Croatia.

1 Unit – USD 5.00 Base shipping cost included:

View cart and checkout:

If you got redirected back here and cannot buy, it means it’s out of stock, sorry.

Please note I cannot ship device pre-programmed with any image.

Payment and Shipping

Payment is processed by PayPal. PayPal offers a secure payment process whilst keeping your payment details private. PayPal WILL NOT disclose your Card Payment Information to me. Details such as Card Number, Expiry Date, and CVV number will only be known to PayPal. PayPal WILL send information such as your PayPal Email Address and the Shipping Address you have registered to your PayPal account. It is up to you to keep this information up-to-date as this is the email contact and shipping address we will use to contact you and where to ship your purchase. It is strongly advised that you email us with your current Contact Email and Shipping Address after you make a purchase to confirm these details, and optionally provide a phone number if you are comfortable sharing it with us for better package delivery experience.

I will combine and ship as many items as possible in one package if you purchase more than 1 item, as long as multiple items can be fitted in one package and can be covered by insurance. Please pay first, I will refund you the shipping cost once I have handled the package.

All shipment originate from China, are handled by Yuntu Express and are by air. Shipping usually takes 3 to 10 days depending on where you are.

Return and Refund

If you need a refund before the package has been picked up by express service, send email with detail of your purchase. Shipping cost is non-refundable.

If you need to return the product for a refund please contact using email so that we can work something out. By submitting a order you confirm that you are aware of: a return and refund may not be possible depending on the location.

Turnaround Time

Once you have paid the bill please allow up to 24 hours for me to respond and confirm your order. Handling time is usually 3 to 7 days before I can email you with a shipment tracking number. Sorry for any inconvenience as I don’t work full time on this.

Purchasing-related Contact

For purchase related issue and/or to confirm your address/email, please mail to: [email protected]. In case of urgent matter, an email may be sent to contact you from either my personal email listed in the about page, or from an @sa1tech.com email address. All of these described email addresses are legit.

We may use old stock of packaging material from other products. You may receive material with “Yanyu” or “StrictFish” marking/packaging. You may receive material sent by SA1 Technology Co., Ltd.. “Yanyu”, “StrictFish” are trademarks of SA1 Technology Co., Ltd.. SA1 Technology Co., Ltd. is an affiliated company. All packages are packed under video/still image recording and weighted before shipment. Any scam activity will be recorded and reported to law enforcement agency local to the buyer.

Resources

Production Record

Lot No.Date Code
(YYWW)		Batch Size (pcs)Date Available /
Date Expected		Status
1250640Feb. 13, 2025Sold out
2250760Week 10, 2025Production
2+250740Planned
3Planned
Lot 1

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